When you have severe diarrhea, the priority is replacing lost fluids and electrolytes first, then eating small amounts of bland, low-fiber foods as soon as you can tolerate them. Waiting too long to eat doesn’t help recovery. Current evidence shows that resuming food early carries no additional risk of prolonged diarrhea or vomiting compared to delaying meals.
Fluids Come First
Severe diarrhea drains water and electrolytes fast. Plain water alone won’t replace the sodium and potassium you’re losing, so an oral rehydration solution is the single most important thing you can consume. You can make one at home using the World Health Organization’s formula: combine 4¼ cups of water with ½ teaspoon of salt and 2 tablespoons of sugar. Stir until dissolved and sip steadily throughout the day.
If you want something with more flavor, a broth-based version works well. Dissolve one regular-sodium bouillon cube in 4 cups of water, add ¼ teaspoon of salt and 2 tablespoons of sugar. The sodium in the broth contributes to electrolyte replacement while tasting more like food.
Sports drinks are a common substitute, but they’re not ideal. A typical sports drink contains about three times less sodium and nearly twice as much sugar as a proper rehydration solution. That extra sugar without enough sodium can actually pull more water into the gut and worsen loose stools. If a sports drink is all you have, dilute it roughly half and half with water and add a small pinch of salt.
What to Eat as Soon as You Can
You may have heard of the BRAT diet (bananas, rice, applesauce, toast), and those foods are still fine choices. But you don’t need to limit yourself to just those four items. The goal is to eat foods that are easy to digest, low in fat, and high in soluble fiber, which slows the movement of food through your digestive tract and helps firm up stool.
Good options include:
- Oatmeal made with water instead of milk
- White rice or plain pasta
- Bananas, especially slightly underripe ones
- Applesauce (unsweetened)
- Peeled, boiled potatoes
- Plain crackers or white toast
- Chicken broth or clear soups
- Steamed or boiled chicken without skin
These foods share a common trait: they’re low in insoluble fiber, the type that speeds food through the gut. Soluble fiber, found in oatmeal, bananas, applesauce, and potatoes, does the opposite. It absorbs water in the intestine and slows transit time, which is exactly what you want.
Start with small portions. A few bites of banana and a handful of crackers is a reasonable first meal. If that stays down, eat again in an hour or two. Frequent small meals are easier on your system than three large ones.
Foods and Drinks to Avoid
Some foods will actively make diarrhea worse. Greasy, fried, or heavily spiced foods are hard to digest even when you’re healthy, and they can trigger cramping and urgency during a bout of diarrhea. Raw vegetables, whole grains, nuts, and seeds are high in insoluble fiber and can speed things up when you need them to slow down.
Sugar alcohols are a surprisingly common trigger that many people overlook. Sorbitol, mannitol, xylitol, and maltitol are used as sweeteners in sugar-free gum, candies, and some liquid medications. As little as 5 grams of sorbitol can cause gas and cramping, and doses above 20 grams reliably cause diarrhea on their own. Check the labels of anything marked “sugar-free” and avoid it until you’ve recovered. Sorbitol also occurs naturally in certain fruits: apples, pears, peaches, plums, prunes, apricots, and dried fruits like dates and raisins. Stick to bananas and applesauce instead.
Caffeine stimulates the intestines and can increase the frequency of loose stools. Skip coffee, energy drinks, and strong tea. Alcohol is dehydrating and irritates the gut lining. Carbonated drinks can add gas and bloating to an already uncomfortable situation. Fruit juices, especially apple and pear juice, are high in sugar and sorbitol, which can worsen osmotic diarrhea by pulling extra water into the intestine.
Why You Should Skip Dairy for Now
A stomach bug or severe infection can temporarily damage the lining of your small intestine, which is where lactase, the enzyme that breaks down dairy, is produced. This means you can develop a temporary lactose intolerance even if you normally digest milk just fine. Undigested lactose draws water into the gut, causing more diarrhea, bloating, and cramping.
This secondary lactase deficiency is reversible. Once the intestinal lining heals, your ability to digest dairy returns. For most people, that means avoiding milk, ice cream, soft cheeses, and cream-based foods for a few days to a week after symptoms resolve. Hard cheeses and yogurt are generally better tolerated because they contain less lactose, but during the worst of it, skipping dairy entirely is the safest approach.
Whether Probiotics Help
Probiotics get recommended often for diarrhea, but the evidence is more nuanced than the marketing suggests. One well-designed study tested a specific probiotic strain (Lactobacillus GG) during acute infectious diarrhea. Among people who had already been sick for more than two days, the probiotic group returned to normal stools about 23 hours sooner (51 hours versus 74 hours) and had roughly half as many diarrheal episodes. However, when looking at all participants regardless of how long they’d been sick, the difference wasn’t statistically significant.
In practical terms, probiotics are unlikely to hurt and may modestly shorten a prolonged episode. Yogurt with live cultures (if you can tolerate dairy), fermented foods like miso, or a probiotic supplement are all options. Don’t expect dramatic results, and don’t rely on them as a substitute for rehydration and careful eating.
How to Transition Back to Normal Food
Once you’ve had formed stools for 24 hours, you can start reintroducing your regular diet gradually. Add one food group at a time so you can identify anything that triggers a setback. Cooked vegetables before raw. Lean proteins before fatty meats. Small amounts of dairy before a full glass of milk.
Most people can return to their normal diet within three to five days of symptoms clearing. If certain foods keep triggering loose stools even after a week, that temporary lactase deficiency or gut irritation may still be healing. Give it more time and stick with the gentler options a bit longer.
Signs That Need Medical Attention
Severe diarrhea lasting more than two days in an adult warrants a call to your doctor. The same applies if you’re experiencing six or more loose stools per day, a high fever, severe abdominal or rectal pain, or stools that are black, tarry, or contain blood or pus. Changes in mental state like unusual irritability, confusion, or lack of energy suggest dehydration has become serious.
Certain groups are at higher risk for complications: adults over 65, pregnant people, anyone on antibiotics, and those with weakened immune systems. For infants and young children, the timeline is shorter. Diarrhea lasting more than one day, any fever in infants, or refusal to drink fluids for more than a few hours are all reasons to contact a pediatrician promptly.