Is it better to eat or fast with diarrhea?

November 25, 2025 •

4 min read

According to the NIDDK, most medical experts advise against fasting during acute diarrhea. For most people, consuming specific, easily digestible foods is far more beneficial for recovery and preventing complications, such as dehydration, than fasting with diarrhea.

Quick Summary

Eating a bland diet in small, frequent portions is generally recommended over fasting for managing diarrhea. This approach helps replenish lost nutrients and electrolytes while providing energy for recovery. The focus should be on hydrating with water and electrolyte-rich fluids and gradually introducing low-fiber, binding foods to firm up stool.

Key Points

Eating is safer than fasting: Medical experts advise against fasting during acute diarrhea due to the risk of complications like dehydration and electrolyte imbalance.
Hydration is critical: Drinking plenty of fluids, including water, broths, and oral rehydration solutions, is the most important step to prevent dangerous dehydration.
Start with bland foods: Once you can tolerate liquids, introduce low-fiber, binding foods like bananas, white rice, applesauce, and toast to help firm stools.
Eat small, frequent meals: Instead of three large meals, opt for 5-6 smaller meals throughout the day to avoid overwhelming your sensitive digestive system.
Avoid irritants: Stay away from fatty, fried, spicy, and high-fiber foods, as well as dairy, caffeine, and alcohol, as these can worsen diarrhea.
Listen to your body: Eat only when you feel hungry and stop when you are full. The gradual introduction of food is key to recovery.

The Dangers of Fasting with Diarrhea

While the impulse to fast during an upset stomach may seem logical, it is not recommended by medical experts. Fasting, especially with diarrhea, can lead to serious health complications, primarily due to the risk of dehydration and electrolyte imbalance. Diarrhea causes the rapid loss of fluids and essential minerals, such as sodium and potassium. Fasting prevents these from being replenished, exacerbating the problem. Severe dehydration, if left untreated, can lead to serious health issues, including kidney damage and shock. Additionally, without any food, your body is deprived of the energy needed to fight off the underlying infection or illness causing the diarrhea, potentially prolonging your recovery.

Risks associated with fasting during diarrhea:

Dehydration: Your body loses a significant amount of water and fluids with every loose bowel movement, and fasting prevents you from replacing them.
Electrolyte Imbalance: Minerals like sodium, potassium, and chloride are crucial for nerve and muscle function. Diarrhea depletes them, and fasting compounds the issue.
Malnutrition: A prolonged lack of nutrients, even for a short fast, can hinder the body's ability to repair and heal itself.
Fatigue: Without caloric intake, your body's energy levels will plummet, leaving you feeling weak and exhausted.
Prolonged Recovery: Starving the body of the fuel it needs can delay the recovery process.

The Benefits of Eating with Diarrhea

Rather than fasting, the consensus is to eat small, frequent meals of easily digestible, bland foods. This helps provide the body with energy, replace lost nutrients, and can even help firm up your stool. The key is to start slowly and choose foods that won't irritate your sensitive digestive system. The BRAT diet (Bananas, Rice, Applesauce, Toast) is a classic example of this approach, though modern guidance includes a broader range of bland foods.

Dietary Strategy During Diarrhea:

Start with Clear Liquids: Begin with sips of water, clear broth, or an oral rehydration solution to stabilize fluids.
Introduce Bland Foods: Once you can tolerate liquids, gradually add in low-fiber, binding foods.
Small, Frequent Meals: Overwhelming the digestive system with large meals can worsen symptoms. Aim for 5-6 small meals throughout the day.
Listen to Your Body: Only eat when you feel hungry and stop when you feel full. Don't force yourself to eat.
Gradual Return to Normal: As symptoms improve, you can slowly reintroduce other low-fat, cooked foods.

Comparison: Eating vs. Fasting with Diarrhea


Feature	Eating with Diarrhea	Fasting with Diarrhea
Hydration	Facilitates replenishment of lost fluids and electrolytes.	Greatly increases the risk of dehydration and electrolyte imbalance.
Nutrient Intake	Provides essential vitamins, minerals, and calories for recovery.	Deprives the body of the necessary fuel to fight off infection and heal.
Digestive Impact	Consuming small, bland meals is gentle on the irritated gut.	May lead to bile buildup and irritation upon refeeding.
Symptom Management	Certain foods like bananas and rice can help firm stools.	Can worsen fatigue and weakness due to lack of energy.
Speed of Recovery	Proper nutrition can support a quicker and more effective recovery.	Can potentially prolong recovery by weakening the body.

Foods to Eat and Avoid

During a bout of diarrhea, it's not just about eating, but about eating the right things. Certain foods can soothe the digestive tract and help with recovery, while others can irritate it further.

Recommended Foods (BRAT-friendly and more):

Bananas: High in potassium and help firm up stool.
White Rice: Low in fiber and easy to digest.
Applesauce: Contains pectin, a soluble fiber that can help reduce diarrhea.
White Toast: Made from refined flour, it's easily digestible.
Broth-based Soups: Help replace lost fluids and sodium.
Boiled or Baked Potatoes: Excellent source of potassium, especially when peeled.
Lean Protein: Baked chicken or turkey without the skin is a good option.
Probiotics: Yogurt with live cultures can help restore good gut bacteria, but avoid if lactose intolerant.

Foods and Drinks to Avoid:

High-Fat and Fried Foods: Difficult for the digestive system to process and can worsen symptoms.
Spicy Foods: Can irritate the stomach and gut lining.
Dairy Products: Can be hard to digest due to temporary lactose intolerance that sometimes accompanies diarrhea.
High-Fiber Foods: Insoluble fiber (found in whole grains, nuts, and raw vegetables) can speed up bowel movements.
Caffeine and Alcohol: Both can act as diuretics and stimulate the digestive tract.
Artificial Sweeteners and High-Sugar Foods: Can have a laxative effect.

The Critical Role of Hydration

Beyond food choices, maintaining proper hydration is the single most important aspect of managing diarrhea. Dehydration is the primary risk associated with diarrhea and can be dangerous, especially for children and the elderly. You should drink small, frequent amounts of fluid throughout the day, and even more after each loose bowel movement.

Options for rehydration include:

Water: The most essential fluid for staying hydrated.
Oral Rehydration Solutions (ORS): These contain the optimal balance of water, glucose, and electrolytes for rapid absorption.
Clear Broths: Help replenish sodium and provide some sustenance.
Sports Drinks: Can replace electrolytes, but choose lower-sugar options and dilute if necessary.

Conclusion

In summary, the question of whether to eat or fast with diarrhea has a clear answer: it is better to eat, provided you make the right food choices. Fasting can increase the risk of severe dehydration and electrolyte imbalance, and it deprives your body of the energy needed for recovery. By consuming small, frequent portions of bland, easily digestible foods—like those in the BRAT diet—and prioritizing hydration, you can help soothe your digestive system and support a quicker recovery. Always listen to your body and return to a normal, balanced diet gradually as your symptoms subside. If symptoms persist or worsen, consult a healthcare professional to rule out more serious underlying conditions.

Frequently Asked Questions

No, it is generally not recommended to fast for more than a few hours with diarrhea. Fasting increases the risk of dehydration and electrolyte imbalance, which are more serious health concerns than a temporary upset stomach.

The BRAT diet consists of Bananas, Rice, Applesauce, and Toast. These foods are bland, low in fiber, and can help firm up stool. While it is a good starting point, modern advice suggests expanding beyond just these four items to ensure adequate nutrition.

Drinking water is essential, but also include clear broths, oral rehydration solutions (like Pedialyte), and sports drinks (diluted and low-sugar) to replenish lost electrolytes and sodium.

After starting with clear liquids, you can gradually introduce bland, low-fiber solid foods like those in the BRAT diet. Listen to your body and increase your intake slowly as your symptoms improve.

Probiotics, found in some yogurts and supplements, can help restore the balance of good bacteria in your gut. However, some people may have a temporary lactose sensitivity with diarrhea, so consider non-dairy probiotic sources if needed.

While recovering from diarrhea, it's best to limit dairy, as many people experience a temporary intolerance to lactose. An exception might be probiotic-rich yogurt, but monitor your symptoms carefully.

Avoid fatty or fried foods, spicy dishes, high-fiber foods like whole grains and raw vegetables, caffeine, and alcohol. These can all irritate the digestive system and prolong symptoms.