Most cases of diarrhea clear up on their own within a few days, but the right combination of fluids, food choices, and over-the-counter treatments can shorten the episode and keep you comfortable. The two main OTC options are loperamide (Imodium) and bismuth subsalicylate (Pepto-Bismol), and what you eat during a bout matters more than most people realize.
Over-the-Counter Medications
Loperamide is the faster, more effective option for acute diarrhea. It works by slowing down the movement of your intestines, giving your body more time to absorb water from stool. A head-to-head comparison published in The American Journal of Medicine found that time to the last unformed stool was significantly shorter with loperamide than with bismuth subsalicylate, and once symptoms improved, relief lasted longer. For most adults, you take an initial dose after the first loose stool and then a smaller dose after each subsequent one, up to a daily limit.
Bismuth subsalicylate is a gentler choice that coats the lining of your stomach and intestines. It’s better suited for milder cases or when nausea accompanies the diarrhea. One thing that catches people off guard: bismuth reacts with tiny amounts of sulfur in your saliva and digestive tract, forming a harmless black compound. This can turn your tongue and stool dark black. It looks alarming but is completely normal and clears up after you stop taking it. If the discoloration persists for several days after your last dose, check with a pharmacist.
One important caution: avoid anti-diarrheal medications if you have bloody stools or a high fever. These can be signs of a bacterial infection like dysentery, and slowing your gut in that situation can trap the infection inside and make things worse. The FDA approves loperamide for children over age 2, but for young kids, fluid replacement is far more important than medication.
Fluids Come First
Dehydration is the real danger with diarrhea, not the diarrhea itself. Your body loses water and electrolytes with every loose stool, and replacing them is the single most important thing you can do. Water alone isn’t ideal because it doesn’t replace lost sodium and potassium. Oral rehydration solutions (sold as Pedialyte or store-brand equivalents) are specifically designed for this. For adults, broth, diluted juice, and sports drinks also help, though sports drinks tend to be high in sugar.
Signs that dehydration is becoming serious include excessive thirst, dry mouth, dark-colored urine, dizziness, and producing very little urine. In children, watch for no wet diaper in three or more hours, sunken eyes or cheeks, and unusual sleepiness or irritability.
What to Eat (and What to Skip)
The classic BRAT diet (bananas, rice, applesauce, toast) has been a go-to recommendation for decades, and those foods are reasonable choices since they’re bland, starchy, and easy to digest. But the CDC notes that relying only on the BRAT diet for too long can leave you short on calories and protein, which slows recovery. A better approach is to return to your normal diet fairly quickly, focusing on starches, cereals, yogurt, fruits, and cooked vegetables.
Foods to avoid while your gut is recovering: anything high in fat, very sugary drinks and candy, dairy milk (yogurt is usually fine), spicy food, caffeine, and alcohol. These can all irritate your intestines or pull more water into your bowel, making things worse.
Probiotics
Probiotics can meaningfully shorten an episode of diarrhea, especially when it’s caused by an infection. A Cochrane review of clinical trials found that probiotics reduced the duration of diarrhea by roughly a day and a half in children with rotavirus infections. The yeast Saccharomyces boulardii and the bacterial strain Lactobacillus GG (commonly sold as Culturelle) have the strongest evidence behind them. Lactobacillus GG appeared particularly effective against rotavirus, with one trial showing it reduced stool frequency from about 2 episodes on day three down to less than 1.
You can find these as standalone supplements or in certain yogurts. They’re safe for most people and worth trying alongside other treatments, though they work best when started early in the illness.
Zinc for Children
For children with diarrhea, zinc supplementation is a well-supported treatment. The World Health Organization recommends 20 mg of zinc per day for 10 to 14 days for children (10 mg per day for infants under six months). Zinc has been shown to reduce both the duration and severity of diarrhea episodes. This is most relevant in settings where zinc deficiency is common, but it’s a safe and inexpensive option worth discussing with your pediatrician.
Warning Signs That Need Medical Attention
Most diarrhea resolves without medical help, but certain symptoms signal something more serious. For adults, see a doctor if diarrhea lasts more than two days without improvement, if you develop a fever above 102°F, if you see blood or black color in your stool (and you haven’t been taking bismuth subsalicylate), or if you have severe abdominal pain. Signs of significant dehydration, like dizziness, very dark urine, or barely urinating at all, also warrant a visit.
For children, the timeline is tighter. Seek medical attention if diarrhea doesn’t improve within 24 hours, if there’s a fever over 102°F, or if you notice any signs of dehydration like dry diapers, sunken eyes, or skin that stays pinched when you lift it rather than springing back. Severe diarrhea, defined as more than 10 bowel movements a day or fluid losses that clearly outpace what the child is drinking, can cause dangerous dehydration quickly.