Natural stool hardening: 3 ways to fix loose stools

Loose stools, frequent bowel movements, or undigested stools are not only inconvenient but also lead to fatigue, dehydration, and impact daily life. Acute diarrhea is quite common, and most cases can improve on their own, but if it persists, recurs, or is accompanied by unusual symptoms, it should not be taken lightly.

If you are looking for ways to harden your stools, treat loose stools, or are wondering about how to cure undigested stools, this article will help you identify common causes and practical ways to improve it through diet, lifestyle habits, and treatment options. Tiptory will guide you on what to do first to gradually stabilize your stools, and also indicate when to see a doctor to avoid prolonged conditions or masking a digestive issue that needs treatment.

What to eat to harden stools?

Prioritize starchy, easily digestible foods

• When experiencing diarrhea or loose stools, you can prioritize simple foods like white rice, white bread, potatoes, porridge, or oatmeal.

• Bananas and apples can also be included in your diet if suitable. These foods are easy to eat and can help provide energy when your intestines are sensitive.

• The BRAT diet (bananas, rice, apples, and toast) was once used to support people with diarrhea. However, experts do not recommend eating only BRAT for an extended period because this diet does not provide sufficient energy, protein, and essential nutrients.

Temporarily avoid foods that can make stools looser

• Limit fatty or fried foods as they can upset the digestive system even more.

• Avoid spicy foods if they increase abdominal pain or bowel movements.

• Limit foods and drinks containing artificial sweeteners like sorbitol, mannitol, or xylitol, as some can cause bloating or make stools looser.

• If you notice that milk or dairy products worsen your symptoms, you can temporarily reduce your intake during diarrhea.

Eat enough for bowel recovery

• Do not fast completely to try to harden stools. When you can eat, divide your meals into several small, easily digestible portions.

• Drink enough water and supplement with electrolyte rehydration solutions when experiencing severe diarrhea to prevent dehydration.

• If diarrhea is prolonged, recurrent, or accompanied by blood in the stool, high fever, severe abdominal pain, or signs of dehydration, you should see a doctor instead of just trying to treat loose stools with diet.

Part 1: How to eat to form solid stools

Tip 1: What to eat to make stools thicker?

Prioritize soft, easily digestible foods

• When experiencing diarrhea or loose stools, you can start with simple foods like white rice, toast, boiled potatoes, bananas, porridge, or cereals. These are often well-tolerated when the digestive tract is sensitive.

• Bananas, rice, apples, and bread are often referred to as the BRAT diet. However, experts do not recommend eating only BRAT for an extended period because this diet is too restrictive and may not provide enough nutrition.

• When appetite returns, most people with acute diarrhea can gradually return to their normal diet instead of fasting or eating only one food group.

Limit foods that can worsen diarrhea

• Temporarily reduce high-fat foods such as fried foods, fast food, and overly greasy dishes if they increase symptoms.

• Limit caffeinated beverages, alcohol, and foods high in simple sugars.

• Avoid or reduce products containing sugar alcohol sweeteners like sorbitol, mannitol, or xylitol, as they can cause diarrhea in some people.

• If lactose intolerance develops after an episode of diarrhea, milk and dairy products may temporarily make stools looser.

Don't just focus on hardening stools

• The most important goal when you have diarrhea is rehydration and electrolyte replacement, not trying to thicken stools immediately. Drinking enough water and using electrolyte rehydration solutions when needed helps reduce the risk of dehydration.

• Do not fast to treat loose stools. When you can eat, choose easily digestible foods, start with small amounts, and gradually increase as tolerated.

• If undigested stools or loose stools persist, recur, are accompanied by high fever, severe abdominal pain, blood in the stool, or signs of dehydration, a doctor should evaluate it instead of just adjusting the diet.

Tip 2: Reduce fiber during acute diarrhea

Temporarily reduce fiber if you have acute diarrhea

• When experiencing loose stools or acute diarrhea, you can temporarily reduce foods very rich in fiber, especially if they cause bloating, cramping, or more frequent bowel movements.

• However, there is no basis for rigidly applying 13g of fiber per day for everyone. NIDDK guidelines state that people with acute diarrhea generally do not need to fast or follow an overly restrictive diet; when they can eat, most can return to a normal diet.

• Therefore, if the goal is to harden stools, you should adjust your fiber intake based on your body's tolerance rather than setting a fixed number.

Differentiate fiber for acute diarrhea and prolonged diarrhea

• It should not be understood that less fiber is always better for the intestines. For soft stools or prolonged diarrhea, the cause is the determining factor in how to adjust the diet.

• Some people can improve undigested stools or loose stools by adjusting the type and amount of fiber appropriately. If symptoms persist, a specialist can guide dietary changes based on the specific cause and food diary.

• Conversely, fiber remains an important part of a healthy diet. It should not be cut for extended periods solely to treat loose stools without identifying the cause.

Gradually increase fiber when stools are stable

• When acute diarrhea subsides, gradually reintroduce vegetables, fruits, whole grains, and high-fiber foods into your diet if your body tolerates them well.

• Increasing fiber too quickly can cause bloating, abdominal distension, or discomfort. Therefore, gradual changes are usually easier to adapt to.

• Adults are typically recommended about 22–34g of fiber per day depending on age and gender, but specific needs may vary.

Prioritize rehydration over just trying to thicken stools

• In acute diarrhea, the primary concern is dehydration and electrolyte imbalance. Drinking enough water and using electrolyte rehydration solutions when needed helps reduce the risk of dehydration.

• If diarrhea lasts longer than 2 days in adults, more than 6 bowel movements per day, high fever, severe abdominal pain, bloody stools, or signs of dehydration, you should see a doctor to find the cause instead of continuing to self-adjust fiber intake.

Tip 3: Eating small amounts helps reduce diarrhea

Divide meals into smaller portions instead of eating too much at once

• When experiencing loose stools, try dividing your meals into several small portions throughout the day instead of eating three large meals. This approach can help you tolerate food better, especially when you are bloated, nauseous, or experiencing digestive discomfort.

• There's no need to force yourself to fast to harden stools. According to NIDDK, when appetite returns, people with acute diarrhea can usually resume their normal diet as tolerated.

• Eat slowly, chew thoroughly, and avoid consuming a large amount of food in one meal. If a meal exacerbates symptoms, reduce the portion size and divide it into smaller meals.

Prioritize easily digestible foods

• You can choose rice, porridge, potatoes, bread, bananas, or familiar foods that your body tolerates well.

• Temporarily limit high-fat foods, fried foods, alcohol, caffeinated beverages, and foods high in simple sugars if they worsen loose stools or abdominal pain.

• If you're looking to treat loose stools, the important thing is not to force stools to harden quickly, but to maintain proper nutrition and adequate hydration and electrolytes for the body to recover.

Monitor your body's reaction

• Keeping a record of what you've eaten, when symptoms appear, and the number of bowel movements can help identify which foods worsen the condition, especially when diarrhea is prolonged or recurrent.

• If diarrhea lasts longer than 2 days in adults, more than 6 bowel movements per day, high fever, severe abdominal pain, bloody stools, or signs of dehydration, you should see a doctor to determine the cause instead of just self-adjusting your diet.

Tip 4: Prioritize low-fat dishes

Choose low-fat, easily digestible foods

• When experiencing loose stools, prioritize low-fat dishes such as skinless poultry, lean meat, fish, eggs, and low-fat milk or dairy products if your body tolerates them well.

• Boiled, steamed, baked, or pan-fried dishes with little oil are generally more suitable than heavily fried or greasy dishes. A high-fat diet can worsen diarrhea in some people.

• There's no need to completely eliminate fat. The goal is to reduce high-fat foods during the diarrhea phase to make digestion more comfortable, rather than adopting an overly restrictive diet.

Limit fried, fatty, and oily dishes

• Temporarily avoid dishes like fried foods, fast food, cheesy pizza, fatty meats, french fries, and dishes prepared with a lot of oil.

• Cream sauces, rich gravies, mayonnaise, butter, or cream can significantly increase the fat content of a meal even if the main dish doesn't appear overly oily.

• If you notice that a specific dish causes loose stools or increased abdominal pain, temporarily reduce that dish and monitor your body's reaction. Keeping a food diary can help identify symptom triggers.

Eat easily digestible yet nutritious meals

• You can combine white rice, pasta, or white bread with fish, lean meat, skinless chicken, and cooked vegetables if your body tolerates them well.

• When acute diarrhea subsides, there's no need to maintain a low-fat or low-fiber diet for too long. You can gradually return to your normal diet as symptoms improve.

• If you're looking to harden stools, prioritize reducing foods that clearly worsen symptoms rather than eliminating too many food groups at once.

Don't forget to rehydrate

• Adjusting food is only part of treating loose stools. When you have diarrhea, you need to pay attention to replenishing fluids and electrolytes to prevent dehydration.

• If diarrhea is prolonged, recurrent, or accompanied by blood in the stool, severe abdominal pain, severe vomiting, or signs of dehydration, you should be evaluated by a doctor to find the cause instead of just changing your diet.

Tip 5: Reduce sugar for more stable stools

Limit added sugar when you have diarrhea

• If you are experiencing loose stools, you should reduce soft drinks, milk tea, candies, desserts, and sugary fruit juices. High amounts of simple sugars can draw water into the intestines and worsen diarrhea in some people.

• There's no need to completely eliminate all types of sugar from food. The important thing is to limit sources of added sugar and high-sugar beverages during the period when symptoms are evident.

• When reading nutrition labels, pay attention to the amount of sugar and sweeteners to easily control your total daily sugar intake.

Avoid sweeteners that can make stools looser

• Some sugar alcohol sweeteners like sorbitol, mannitol, and xylitol can cause bloating or diarrhea in some people, especially when consumed in large amounts.

• They are often found in sugar-free gum, sugar-free candies, and some products advertised as low-sugar. If you notice these products worsen your symptoms, you should temporarily stop using them.

• If you are looking to harden stools, identifying and limiting the right irritating foods will be more helpful than overly restricting your diet.

Don't confuse sugary drinks with rehydration solutions

• Do not use soft drinks, sugary fruit juices, or sports drinks to replace electrolyte rehydration solutions when you have diarrhea. High sugar content can worsen diarrhea.

• Conversely, oral rehydration solutions (ORS) contain glucose in a balanced ratio with sodium and other electrolytes. Glucose helps increase sodium and water absorption in the intestines, even during diarrhea.

• Therefore, if you need to treat loose stools and prevent dehydration, prioritize ORS prepared according to instructions instead of drinking concentrated sugar water or regular soft drinks.

Return to normal eating when symptoms subside

• You should not fast or maintain an overly restrictive diet just to cure undigested stools. When appetite returns, most people with acute diarrhea can gradually return to a normal diet.

• If loose stools persist or recur frequently, keep a record of the foods, drinks, and sweeteners you've consumed to identify related factors, and talk to your doctor if symptoms don't improve.

Tip 6: Choose foods that help stabilize stools

Prioritize easily digestible foods during diarrhea

• When experiencing frequent loose stools, you can prioritize simple, easily digestible foods like white rice, potatoes, bananas, toast, pasta, or eggs if your body is eating normally.

• NIDDK also notes rice, bananas, and toast as options that can be consumed during diarrhea. However, there is no evidence that you need to eat only "stool-thickening" foods to treat loose stools.

• If you want to harden stools, view the above foods as easy-to-eat options during the period when symptoms are pronounced, rather than considering them a mandatory diet.

Eat according to your body's tolerance

• When appetite returns, people with acute diarrhea can usually gradually return to a normal diet, even if they still have diarrhea. Experts do not recommend fasting or adopting an overly restrictive diet.

• Temporarily limit foods that tend to worsen symptoms, such as greasy fried foods, alcohol, caffeinated beverages, foods high in simple sugars, and some products containing sugar alcohols like sorbitol or mannitol.

• If a specific food causes you abdominal pain or looser stools, temporarily reduce that food and monitor your reaction instead of eliminating too many food groups at once.

Rehydration is still the priority

• Diarrhea causes the body to lose water and electrolytes. Therefore, in addition to food choices, drink enough water and use electrolyte rehydration solutions when needed to prevent dehydration.

• Do not force yourself to eat many "binding" foods to cure undigested stools, because the most important goal in acute diarrhea is still to maintain adequate fluids, electrolytes, and nutrition.

Know when to see a doctor

• If diarrhea lasts longer than 2 days in adults, more than 6 bowel movements per day, high fever, severe abdominal pain, bloody or black stools, severe vomiting, or signs of dehydration, a doctor needs to evaluate it.

• If soft stools or undigested food in stool occur frequently, do not rely solely on food to manage the condition. The cause may be related to infection, food intolerance, medication side effects, or gastrointestinal diseases, and needs to be properly identified.

Tip 7: Limit foods that can cause loose stools

Temporarily reduce laxative foods

• When experiencing loose stools, you should temporarily reduce foods that may stimulate bowel movements or soften stools if you notice they worsen your symptoms.

• Some options to be aware of include prunes, prune juice, figs, legumes, bran, and some dried fruits. Prunes and prune juice, in particular, can have a laxative effect due to substances like sorbitol.

• It's not necessary to eliminate these foods entirely. Everyone's reaction is different, so adjust your diet based on actual symptoms.

Limit spicy foods if they irritate your gut

• Chili, curry, and overly spicy dishes can increase digestive discomfort or diarrhea in some people. If you notice that spicy food makes your stools loose, reduce your spice intake for a few days.

• This is not a mandatory rule for everyone. If you tolerate spicy food well, you don't necessarily need to avoid it long-term just to harden your stools.

Monitor foods that cause symptoms

• Instead of avoiding too many foods at once, keep a record of what you eat, when you eat it, and your bowel movements. This helps identify more accurately which foods may worsen symptoms.

• Once your stools stabilize, you can gradually reintroduce foods you temporarily reduced in small amounts to test your tolerance.

• If you are trying to treat loose stools, the goal is not to eliminate all potentially laxative foods but to find the right triggers and maintain a nutritious diet.

Don't adopt an overly restrictive diet

• For acute diarrhea, experts do not recommend fasting or an overly restrictive diet. When able to eat, most patients can gradually return to their normal diet.

• During this time, it is still necessary to drink enough water and electrolytes to prevent dehydration. If diarrhea is prolonged, recurrent, or accompanied by blood in the stool, fever, severe abdominal pain, or signs of dehydration, you should see a doctor to determine the cause.

Tip 8: Drink enough water when you have diarrhea

Replenish fluids and electrolytes

• When experiencing loose stools or diarrhea, the body loses fluids and electrolytes. Therefore, the top priority is to drink enough water and replenish electrolytes to prevent dehydration, rather than just focusing on hardening the stools.

• You can drink water, broth, soup, or electrolyte-containing beverages. If diarrhea is severe or there are signs of dehydration, oral rehydration solution (ORS) is a more suitable choice.

• It's not necessary to force yourself to drink exactly 8–10 glasses per day. Fluid needs vary depending on the frequency of bowel movements, degree of dehydration, age, and health status. For adults, MedlinePlus suggests drinking about 8–10 glasses of fluid during the day and an additional glass after each loose bowel movement.

Sip if you are nauseous

• If you have diarrhea and nausea, sip small amounts frequently rather than drinking a large amount at once. This helps the body absorb fluids more easily.

• ORS contains glucose and electrolytes in appropriate proportions, which helps increase water and salt absorption in the intestines. This is why ORS is recommended as the first-line option for rehydration in acute diarrhea with mild to moderate dehydration.

Do not use sugary drinks instead of ORS

• Fruit juice, sugary soft drinks, or high-sugar beverages are not optimal choices for rehydration during diarrhea. High amounts of simple sugars can worsen symptoms in some people.

• If using fruit juice, moderate amounts are preferable, and avoid prune juice as prunes have a laxative effect, which can make stools looser.

• At the same time, limit alcohol and caffeinated beverages during diarrhea as they can exacerbate discomfort or dehydration.

Return to eating when your body allows

• Rehydration does not mean fasting. When appetite returns, most people with acute diarrhea can resume a normal diet as tolerated.

• You can start with easily digestible foods such as rice, potatoes, bread, bananas, eggs, or lean meat if suitable. The goal is to maintain nutrition during recovery, not to force immediate stool hardening.

Know when to see a doctor

• If diarrhea lasts longer than 2 days in adults, worsens, or is accompanied by blood in the stool, fever, severe abdominal pain, or signs of dehydration, a doctor should be consulted.

• If undigested food in stool or loose stools recur frequently, you should not just increase water intake or change food to treat loose stools. In this case, the cause needs to be identified rather than just treating the symptoms.

Part 2: Lifestyle habits to help harden stools

Tip 1: Reduce caffeine when you have diarrhea

Temporarily reduce caffeinated beverages

• When experiencing loose stools, you should reduce or temporarily stop caffeine if you notice symptoms worsen after drinking it. The NIDDK recommends avoiding caffeinated beverages during acute diarrhea as they can exacerbate diarrhea in some people.

• Common sources of caffeine include coffee, tea, caffeinated soft drinks, and energy drinks. The amount of caffeine can vary significantly between beverages, so do not only consider the amount of coffee consumed daily.

• If you are looking to harden your stools, try reducing caffeine for a few days and monitor the frequency and consistency of your bowel movements.

No need to stop caffeine abruptly if you drink it regularly

• People who drink caffeine daily may experience headaches, drowsiness, irritability, or difficulty concentrating when stopping abruptly. Therefore, if caffeine intake is high, it may be reduced gradually rather than cut out entirely immediately.

• You can gradually switch from strong coffee or tea to decaffeinated or low-caffeine options, while prioritizing water and appropriate fluids for rehydration.

• If a specific beverage makes your stools looser, temporarily eliminate that one first. It's not necessary to avoid all foods or drinks if they don't cause symptoms.

Don't mistake caffeine as the sole cause of diarrhea

• Caffeine is only one factor that can worsen symptoms. Diarrhea can also be related to infection, food intolerance, digestive diseases, or medication side effects.

• If undigested food in stool or loose stools are prolonged and recurrent, simply reducing caffeine may not address the underlying cause. In such cases, monitor related foods and beverages and consult a doctor if symptoms persist.

Prioritize rehydration during diarrhea

• Reducing caffeine does not mean reducing fluid intake. When you have diarrhea, your body is at risk of dehydration, so you still need to drink enough water and appropriate electrolytes.

• If diarrhea lasts longer than 2 days in adults, is accompanied by blood or black stools, severe abdominal pain, fever, or signs of dehydration, a healthcare professional should assess the situation rather than just self-adjusting diet.

Tip 2: Check for medications that cause diarrhea

Review current medications

• Some medications can cause loose stools or diarrhea, such as antibiotics, magnesium-containing antacids, laxatives, and some other disease-treating drugs. This is one of the documented causes of acute diarrhea.

• If loose stools begin after taking a new medication, check the package insert to see if this is a documented side effect.

• Do not conclude that medication is the cause based solely on the timing of symptom onset, as diarrhea can also originate from infection, food intolerance, or gastrointestinal disease.

Do not stop prescription medications on your own

• Absolutely do not stop antibiotics or medications for chronic diseases solely for the purpose of hardening stools. Abruptly stopping medication can affect the effectiveness of the initial treatment.

• If you suspect medication is causing diarrhea, talk to your doctor or pharmacist. They can determine if dosage adjustments, medication changes, or continued use are necessary.

• In particular, individuals taking antibiotics and experiencing diarrhea should inform their doctor, as antibiotics can increase the risk of Clostridioides difficile infection, a potential cause of severe diarrhea.

Note on laxatives

• If you are taking laxatives, check the dosage and duration of use. Overdosing or prolonged use can cause diarrhea, dehydration, and electrolyte imbalance.

• Do not continue to use laxatives just because you think diarrhea will resolve on its own after stopping the medication. If you have been using them for a long time or diarrhea is prolonged, you should talk to your doctor to find the cause and adjust safely.

• Some antacids containing magnesium can also cause diarrhea. If symptoms appear after taking medication, a pharmacist or doctor can advise on more suitable options.

Find the cause instead of just trying to treat loose stools

• If you have adjusted medications as advised by a professional but undigested food in stool or loose stools persist, do not continue to self-change medications. Prolonged diarrhea may require investigation to determine the cause.

• Seek medical attention promptly if diarrhea lasts more than 2 days in adults, more than 6 bowel movements per day, high fever, severe abdominal pain, bloody or black stools, severe vomiting, or signs of dehydration.

Tip 3: Probiotics can help with diarrhea

Probiotics can be considered, but should not be seen as a cure for diarrhea

• Probiotics are living microorganisms that can support the gut microbiota. Some studies show that certain probiotic strains can help shorten the duration of diarrhea in some cases, but the effectiveness is not consistent across products and causes of illness.

• Therefore, if you are looking to harden your stools or treat loose stools, probiotics should only be considered a supportive measure, not a replacement for rehydration, electrolyte replenishment, and treatment of the underlying cause.

• The NIDDK notes that current evidence is not sufficient for many experts to routinely recommend probiotics for the treatment or prevention of diarrhea.

Choose the right strain instead of just looking at the probiotic name

• Not all products containing Lactobacillus or Bifidobacterium have the same effect. Probiotic effectiveness depends on the bacterial strain, dosage, and specific condition.

• Therefore, do not assume that simply taking probiotics daily will eliminate loose stools or prevent recurrent diarrhea.

• If you want to use probiotic supplements, especially if you have underlying health conditions, a compromised immune system, or are taking medication, you should consult your doctor first.

You can supplement probiotics from fermented foods

• Some fermented foods like yogurt can provide live microorganisms. However, the ability to provide probiotics and their impact on digestion depend on the specific product.

• There's no need to force yourself to eat a lot of fermented foods to cure undigested food in stool. If a food causes bloating or looser stools, reduce or temporarily stop it.

• When experiencing acute diarrhea, the priority is still to drink enough water, replenish electrolytes, and eat as tolerated. Patients can usually return to their normal diet when their appetite returns.

Monitor the cause if diarrhea recurs

• If loose stools frequently return, do not rely solely on probiotics. Diarrhea can be related to infection, medication side effects, food intolerance, or gastrointestinal diseases.

• If diarrhea lasts longer than 2 days in adults, more than 6 bowel movements per day, high fever, severe abdominal pain, bloody stools, or signs of dehydration, a doctor should assess the situation.

Tip 4: Avoid alcohol when you have diarrhea

Temporarily stop alcohol when stools are loose

• When experiencing loose stools or diarrhea, you should avoid alcohol until your gut stabilizes. The NIDDK recommends avoiding alcoholic beverages during acute diarrhea as they can worsen symptoms.

• Alcohol can also increase the risk of dehydration during diarrhea, when the body already loses a lot of fluids and electrolytes through stool. The NHS also advises avoiding alcohol when showing signs of dehydration.

• Therefore, if the goal is to harden your stools, temporarily giving up alcohol is a simple but worthwhile change.

Especially avoid if drinking alcohol regularly causes diarrhea

• If you notice that drinking alcohol always leads to loose stools, abdominal pain, or frequent bowel movements, consider this a potential trigger.

• Not everyone needs to abstain from alcohol long-term. However, if diarrhea frequently occurs after drinking, you should significantly reduce or stop consumption and observe changes in your digestive system.

• You can record when you drink, the type of beverage, the amount consumed, and your bowel movements to identify the connection more clearly. The NIDDK recommends that a food diary can help identify foods and drinks that worsen diarrhea symptoms.

Rehydrate instead of consuming alcoholic beverages

• When treating loose stools, prioritize water, broth, or oral rehydration solution (ORS) if severe dehydration occurs. ORS helps replenish fluids and electrolytes lost due to diarrhea.

• If you are nauseous, sip small amounts frequently instead of drinking a large amount at once.

• Do not use alcohol to replace water or electrolyte solutions. This is when your body needs "standard water," no extra adventure for your digestive system.

When not to just change your diet

• If undigested food in stool or loose stools are prolonged, recur multiple times, or do not improve after eliminating triggers such as alcohol, you should consult a doctor to find the cause.

• Medical evaluation is needed if diarrhea is accompanied by blood in the stool, severe abdominal pain, fever, severe vomiting, or signs of dehydration.

Part 3: Fastest ways to treat acute diarrhea

Note 1: Reduce fiber when diarrhea is severe

No need to mechanically cut fiber to 13g per day

• When experiencing loose stools or acute diarrhea, there is no general recommendation that everyone must reduce fiber to exactly 13g/day. The NIDDK states that people with acute diarrhea can usually return to their normal diet when their appetite returns and does not recommend fasting or an overly restrictive diet.

• Therefore, if the goal is to harden stool, fiber intake should be adjusted based on the body's tolerance rather than adhering to a fixed amount.

• If some high-fiber foods cause bloating, cramps, or more frequent bowel movements, it may be advisable to temporarily reduce them during severe symptom periods and then reintroduce them once the bowel has stabilized.

Temporarily restrict foods that can make stools looser

• During diarrhea, you can reduce foods that you notice worsen symptoms, such as certain beans, bran, or fruits with laxative effects.

• Prunes and prune juice contain sorbitol and can increase bowel motility in some people. If you are treating loose stools, you should temporarily restrict them if you notice they worsen symptoms.

• At the same time, the NIDDK recommends limiting alcohol, caffeine, high-fat foods, large amounts of simple sugars, and sugar alcohols like sorbitol, mannitol, or xylitol during acute diarrhea.

Increase fiber intake once diarrhea has subsided

• Once stool begins to stabilize, you should not maintain a very low-fiber diet for an extended period. Adults typically need about 22–34 grams of fiber per day, depending on age and gender.

• Reintroduce vegetables, fruits, whole grains, and other fiber sources into your diet gradually to allow your body to adapt.

• Increasing fiber too quickly can cause bloating or discomfort. Therefore, if you need to increase fiber intake, do so slowly and drink plenty of water.

Prioritize rehydration over simply trying to firm up stool

• In acute diarrhea, the most concerning risk is dehydration and electrolyte imbalance. Drinking enough water, broth, or oral rehydration solution helps replace lost fluids.

• You should not fast or eliminate too many food groups just to treat undigested food in stool. When you can eat, maintain adequate nutrition and choose foods that your body can easily tolerate.

Seek medical attention if diarrhea shows abnormal signs

• Contact a doctor if diarrhea lasts more than 2 days in adults, more than 6 bowel movements per day, high fever, severe abdominal pain, bloody or black stool, severe vomiting, or signs of dehydration.

• If loose stools or undigested food in stool persist or recur frequently, simply reducing fiber may not address the underlying cause. In such cases, factors such as infection, medications being used, food intolerance, or gastrointestinal diseases need to be evaluated.



Note 2: Electrolyte replacement for severe diarrhea

Prioritize oral rehydration solutions

• When experiencing frequent loose stools or severe diarrhea, the body not only loses water but also sodium and other electrolytes. Therefore, rehydration and electrolyte replacement are the most important priorities to prevent dehydration, rather than focusing solely on hardening stool.

• You can use oral rehydration solution (ORS) prepared exactly according to the product instructions. ORS contains glucose and electrolytes in appropriate proportions, helping the body absorb water and salts more effectively.

• Older adults, immunocompromised individuals, or those with underlying conditions such as kidney disease or diabetes should consult a doctor about the appropriate type and amount of rehydration solution.

Supplement with additional fluids throughout the day

• In addition to ORS, you can drink plain water, broth, soup, or certain suitable beverages to replenish lost fluids.

• If you are nauseous or find it difficult to drink, take small sips frequently instead of drinking a large amount at once.

• There's no need to stick to a single type of beverage. The goal is to maintain sufficient fluids and electrolytes throughout the duration of diarrhea.

Limit sugary drinks

• Soft drinks, fruit juices with high sugar content, and beverages containing large amounts of simple sugars can worsen loose stools in some people. Therefore, they should not be used as the primary source of rehydration during diarrhea.

• ORS differs from regular soft drinks: ORS is designed with a combination of glucose and electrolytes to aid water absorption, making it more suitable for fluid replacement due to diarrhea.

Eat normally when possible

• Rehydration does not mean fasting. When appetite returns, most people with acute diarrhea can return to their normal diet as tolerated.

• If you are experiencing discomfort with food, you can start with simple dishes like rice, potatoes, bread, bananas, or soft, easy-to-eat foods, then gradually increase portions.

• Do not rely solely on "stool-firming" foods to treat loose stools; restoring water and electrolytes is the immediate priority.

Know when to seek medical attention

• A doctor's evaluation is needed if diarrhea lasts more than 2 days in adults, more than 6 bowel movements per day, high fever, severe abdominal pain, bloody or black stool, severe vomiting, or signs of dehydration.

• If you cannot drink enough water or ORS to replace lost fluids, the risk of severe dehydration increases and requires medical care.



Note 3: Use anti-diarrhea medication at the right time

Consider medication only when appropriate

• For adults with acute diarrhea, some over-the-counter medications like loperamide (Imodium) or bismuth subsalicylate (Pepto-Bismol) can help reduce bowel movement frequency and improve symptoms in some cases. However, medication does not replace rehydration and electrolyte replacement.

• If the goal is to harden stool, you should not self-medicate just because your stool is soft or you have loose stools. First, you need to determine the severity of diarrhea and ensure your body is adequately rehydrated.

Do not use anti-diarrhea medication if there are warning signs

• You should not self-medicate for diarrhea if there is blood in your stool or a fever, as these could be signs of an intestinal infection that requires proper evaluation and treatment.

• Loperamide should also be avoided if inflammatory or bacterial diarrhea is suspected, which carries a risk of complications. The IDSA recommends that antimotility drugs like loperamide only be considered for healthy adults with acute watery diarrhea, after adequate rehydration.

• This medication guideline should not be applied to children without a doctor's prescription. The NIDDK recommends against using over-the-counter anti-diarrhea medications for young children.

Rehydrate before considering medication

• When diarrhea is severe, the priority remains water and electrolytes. Oral rehydration solution (ORS) can help replace lost water and salts.

• Anti-diarrhea medication only plays a role in symptom control. If medication is used but diarrhea continues to worsen or lasts longer than 2 days, contact a doctor.

• Do not try to "lock down" the gut with medication when the body is showing signs of a serious infection. In some intestinal infections, antimotility drugs can increase the risk of complications.

Do not self-treat if diarrhea is prolonged

• If undigested food in stool, loose stools, or recurrent diarrhea persists, anti-diarrhea medication can only mask symptoms without addressing the cause.

• Diarrhea can be related to infection, food intolerance, gastrointestinal disease, or medication side effects. If symptoms persist, a doctor may need to take a medical history and perform tests to find the cause.

• If bloody stool, fever, severe abdominal pain, severe vomiting, dizziness, or signs of dehydration appear, seek medical attention instead of continuing to try to treat loose stools at home.



Note 4: When to seek medical attention for loose stools?

Seek medical attention if diarrhea lasts longer than 2 days

• Acute diarrhea often resolves on its own, but in adults, the NIDDK recommends contacting a doctor if diarrhea lasts longer than 2 days, especially when there are no signs of improvement.

• If loose stools persist or recur frequently, you should not just continue to adjust your diet to harden stool. A doctor may need to find the cause, such as infection, medication side effects, food intolerance, or gastrointestinal disease.

Seek medical attention immediately if warning signs appear

• Prompt medical evaluation is needed if any of the following symptoms occur:

  • Bloody, pus-filled, or black, tarry stools.

  • Severe abdominal or anal pain.

  • High fever.

  • Severe vomiting preventing you from drinking enough water.

  • Signs of dehydration such as increased thirst, dry mouth, reduced urination, dark urine, dizziness, or lightheadedness.

Be especially cautious if having frequent bowel movements

• Adults should contact a doctor if they have 6 or more loose stools in a day, even if no other severe signs have appeared.

• People over 65, pregnant women, those taking antibiotics, or those with weakened immune systems are at higher risk of complications from diarrhea and should consult a doctor sooner.

Do not just try to treat loose stools at home

• Rehydration and electrolyte replacement are still priorities during diarrhea. However, if symptoms persist or abnormal signs appear, trying to treat loose stools with food, probiotics, or over-the-counter medications can delay the process of identifying the cause.

• If undigested food in stool or loose stools persist for many days, a doctor may rely on medical history, clinical examination, and in some cases, tests to find the appropriate cause.

Don't wait until dehydration occurs to address it

• Diarrhea causes the body to lose water and electrolytes; severe dehydration can lead to dangerous complications. Therefore, start rehydrating as soon as diarrhea appears and monitor urine output, thirst, and dizziness.

• If you cannot drink enough water or oral rehydration solution, seek medical care instead of continuing to self-treat at home.



Find the cause if diarrhea persists

Check for lactose intolerance

• If you frequently have loose stools, bloating, excessive gas, or abdominal pain after drinking milk or eating dairy products, lactose intolerance could be a cause to consider. Symptoms usually appear within a few hours of consuming lactose-containing foods.

• You should not completely eliminate milk and dairy products for an extended period. Many people can still tolerate a certain amount of lactose; cutting it out entirely can reduce calcium and vitamin D intake in the diet.

• If lactose is suspected as the cause of prolonged loose stools, a doctor can assess symptoms, diet, and perform a hydrogen breath test if necessary.

Consider irritable bowel syndrome

• Irritable bowel syndrome (IBS) can cause recurrent abdominal pain accompanied by changes in bowel habits, including prolonged diarrhea. This is one of the possible causes when undigested food in stool or loose stools recur without a clear infectious cause.

• If symptoms frequently return, do not just focus on hardening stool by avoiding many types of food. A doctor can use symptoms, dietary history, and necessary tests to rule out other conditions before diagnosing IBS.

• Keeping a food diary and noting when symptoms appear can help identify foods or drinks that worsen the condition.

Actively prevent traveler's diarrhea

• When traveling to areas with limited sanitation or water treatment systems, prioritize sealed bottled water for drinking, brushing teeth, and preparing beverages.

• Avoid ice made from unknown water sources, untreated tap water, raw or undercooked foods, and food not kept properly hot. The CDC also recommends choosing food that is cooked and served hot when traveling.

• For raw fruits and vegetables, only eat them if they have been washed with safe water or if you can peel them yourself. These small habits help reduce the risk of traveler's diarrhea and prevent your trip from turning into an "unwelcome residency" in the bathroom.

Do not just try to treat symptoms

• If you treat loose stools by changing your diet but the condition persists or recurs, you need to find the cause instead of continuing dietary restrictions.

• Prolonged diarrhea can be related to food intolerance, IBS, persistent infection, gastrointestinal disease, or medication side effects.

• If diarrhea lasts more than 2 days in adults, more than 6 bowel movements per day, high fever, severe abdominal pain, bloody stool, or signs of dehydration, you should contact a doctor for evaluation.

References

1. National Institute of Diabetes and Digestive and Kidney Diseases. (2024). Eating, diet, & nutrition for diarrhea. National Institutes of Health.
2. National Institute of Diabetes and Digestive and Kidney Diseases. (2024). Diarrhea. National Institutes of Health.
3. National Institute of Diabetes and Digestive and Kidney Diseases. (2018). Lactose intolerance. National Institutes of Health.
4. Shane, A. L., Mody, R. K., Crump, J. A., et al. (2017). 2017 Infectious Diseases Society of America clinical practice guidelines for the diagnosis and management of infectious diarrhea. Clinical Infectious Diseases, 65(12), e45–e80.
5. Centers for Disease Control and Prevention. (2026). Travelers’ diarrhea. CDC Yellow Book: Health Information for International Travel.
6. Centers for Disease Control and Prevention. (2025). Food and water precautions for travelers. CDC Yellow Book: Health Information for International Travel.
7. Centers for Disease Control and Prevention. (2026). Food and drink considerations when traveling. Travelers’ Health, National Center for Emerging and Zoonotic Infectious Diseases.
8. Centers for Disease Control and Prevention. (2025). Water disinfection for travelers. CDC Yellow Book: Health Information for International Travel.

Content editor: Sidney Bailey Hoang.


Information consulted and verified by expert: William Harris.