Most diarrhea clears up on its own within two to three days, and the most important thing you can do is replace lost fluids. Beyond hydration, a combination of dietary changes, over-the-counter medications, and knowing when the situation is more serious will get most people through an episode comfortably and safely.
Fluids First: Preventing Dehydration
Dehydration is the real danger with diarrhea, not the diarrhea itself. Every loose stool pulls water and essential salts out of your body, and replacing them is the single most effective treatment regardless of the cause. Water alone isn’t ideal because it doesn’t replace the sodium and potassium you’re losing. Sports drinks work in a pinch, but a simple oral rehydration solution is better.
The WHO formula is easy to make at home: dissolve half a teaspoon of salt and two tablespoons of sugar in about four and a quarter cups of water. The sugar isn’t just for taste. It helps your intestines absorb sodium and water more efficiently, which is why the ratio matters. Sip this steadily throughout the day rather than gulping large amounts at once, which can trigger more cramping.
Signs that dehydration is getting ahead of you include a dry mouth, dark yellow urine, dizziness when standing, and feeling unusually weak. In children, watch for no wet diapers for three or more hours, crying without tears, sunken eyes or cheeks, and unusual sleepiness or irritability. These signs mean fluid replacement needs to happen faster, and possibly with medical help.
What to Eat (and Avoid)
You don’t need to stop eating. In fact, continuing to eat helps your gut recover. The key is keeping meals plain and simple. The classic BRAT approach (bananas, rice, applesauce, toast) works well for firming up stool, though it’s not nutritionally complete. Treat it as a one- or two-day strategy, not a long-term plan. You can expand beyond BRAT with oatmeal, boiled or baked potatoes without the skin, dry cereal, and baked chicken with the skin removed.
While your gut is irritated, avoid dairy products, fatty or fried foods, high-fiber vegetables, caffeine, and alcohol. These can all speed up digestion or draw more water into the intestines, making things worse. Once your stools start returning to normal, gradually reintroduce your regular diet over a day or two.
Over-the-Counter Medications
Two main OTC options can help manage symptoms while your body fights off whatever caused the problem.
Loperamide (sold as Imodium) slows the movement of your intestines, giving them more time to absorb water. This firms up stool and reduces the frequency of bathroom trips. The maximum OTC dose for adults is 8 mg per day. It’s useful when you need symptom relief to get through a workday or a flight, but you should avoid it if you have a fever or bloody stools, because in those cases your body may be trying to flush out a bacterial infection.
Bismuth subsalicylate (Pepto-Bismol) takes a different approach. It reduces inflammation in the intestines, slows fluid loss, and can even kill some of the organisms causing the problem. It’s a good option for milder cases and traveler’s diarrhea. However, it contains a compound related to aspirin, so skip it if you have an aspirin allergy, a history of stomach ulcers or bleeding problems, or if you take blood thinners. It’s also not recommended for children or teenagers with flu-like symptoms due to the risk of a rare but serious condition called Reye syndrome. One harmless side effect: it can temporarily turn your tongue and stools black.
When Probiotics Help
Probiotics can shorten an episode of diarrhea, particularly when it’s caused by a stomach bug or follows a course of antibiotics. The yeast strain Saccharomyces boulardii has the strongest evidence behind it. Studies in children show it can speed recovery by roughly a day compared to no treatment. You can find it in supplement form at most pharmacies. Lactobacillus-based probiotics also show benefits, though results vary more across studies. Probiotics are most useful when started early in the illness.
Treating Diarrhea in Children
Children, especially infants and toddlers, dehydrate faster than adults, so fluid replacement is even more critical. Continue breastfeeding or formula feeding as normal. For older children, offer an oral rehydration solution in small, frequent sips. Avoid fruit juices and sugary drinks, which can pull more water into the intestines and worsen diarrhea.
In developing countries where diarrhea is a leading cause of childhood illness, the WHO recommends zinc supplementation: 20 mg per day for 10 to 14 days for children over six months, and 10 mg per day for younger infants. This reduces both severity and duration. In well-nourished children in high-income countries, zinc supplementation is less commonly recommended but still worth discussing with a pediatrician for prolonged episodes.
Traveler’s Diarrhea
Diarrhea picked up while traveling, especially in parts of Asia, Africa, or Latin America, is usually bacterial and follows a predictable pattern. Mild cases that don’t interfere with your plans are best managed with fluids and bismuth subsalicylate alone, without antibiotics. Moderate cases that disrupt your activities can be treated with a short course of antibiotics, and severe cases (incapacitating diarrhea or any episode with blood in the stool or fever) warrant antibiotic treatment right away.
If you’re planning travel to a high-risk area, talk to your doctor beforehand about carrying a standby antibiotic prescription. The CDC notes that a single dose is often as effective as a multi-day course for uncomplicated traveler’s diarrhea. In Southeast Asia specifically, certain antibiotic classes work better than others due to regional resistance patterns, so destination matters when choosing a prescription.
Warning Signs That Need Medical Attention
Most diarrhea is a nuisance, not an emergency. But certain patterns signal something more serious:
- Blood or black color in your stool, which can indicate a bacterial infection or internal bleeding
- Fever above 102°F (39°C), suggesting an infection your body isn’t handling on its own
- More than 10 bowel movements a day, or fluid losses clearly outpacing what you can drink
- Severe abdominal or rectal pain beyond normal cramping
- No improvement after two days in adults, or after 24 hours in children
- Signs of dehydration that aren’t responding to oral fluids: persistent dizziness, little to no urination, or extreme weakness
For infants, the threshold is lower. A baby who hasn’t had a wet diaper in three hours, has a sunken soft spot on the head, or whose skin stays pinched up instead of flattening back down needs prompt evaluation. These are signs of significant fluid loss that oral rehydration alone may not correct.