The fastest way to stop diarrhea is with loperamide (sold as Imodium), an over-the-counter medication that slows intestinal movement and can reduce symptoms within an hour. But loperamide isn’t always the right choice, and several other options, from dietary changes to bismuth subsalicylate, work well depending on your situation. What you should take depends on the cause, how severe it is, and whether you’re treating an adult or a child.
Loperamide: The Fastest OTC Option
Loperamide works by slowing down the muscles in your intestines, giving your body more time to absorb water from stool. For adults and children 13 and older, the standard approach is to take two capsules (4 mg) after the first loose bowel movement, then one capsule (2 mg) after each subsequent loose stool. The maximum is 8 capsules (16 mg) in 24 hours.
Loperamide is effective for garden-variety diarrhea from food that didn’t agree with you, stress, or a mild stomach bug. But there are situations where you should not use it:
- Severe diarrhea after taking antibiotics. This can signal a dangerous bacterial infection where your body needs to flush out the toxin.
- Blood in your stool or high fever. These are signs of dysentery or invasive infection.
- A flare-up of inflammatory bowel disease like ulcerative colitis.
In these cases, slowing your gut down can trap harmful bacteria or toxins inside and make things significantly worse.
Bismuth Subsalicylate for Milder Symptoms
Bismuth subsalicylate (the active ingredient in Pepto-Bismol) takes a different approach. Rather than slowing your intestines, it reduces inflammation in the gut lining and has mild antibacterial properties. It’s a better fit when diarrhea comes with nausea or an upset stomach, since it treats both.
The typical adult dose is 2 tablets every 30 minutes to an hour as needed, up to 16 tablets in 24 hours. It won’t work as quickly as loperamide for stopping frequent trips to the bathroom, but it’s gentler and addresses a broader range of stomach symptoms. Don’t be alarmed if your tongue or stool turns black temporarily. That’s a harmless side effect of bismuth.
One important restriction: bismuth subsalicylate should not be given to children under 12. It contains a compound related to aspirin, which carries a risk of Reye’s syndrome in children, a rare but serious condition affecting the brain and liver. This risk is especially high in kids recovering from the flu or chickenpox.
What to Eat (and Drink) During Diarrhea
You’ve probably heard of the BRAT diet: bananas, rice, applesauce, and toast. It’s fine for a day or two, but there’s no need to limit yourself to just those four foods. A less restrictive approach that includes other bland, easy-to-digest options will give your body the protein and nutrients it needs to recover faster. Good choices include brothy soups, oatmeal, boiled potatoes, crackers, and unsweetened dry cereals.
Once your stomach starts to settle, adding cooked squash, carrots, skinless chicken, fish, eggs, and avocado helps rebuild your energy without irritating your gut. The goal is to avoid fatty, spicy, or high-fiber foods that can make diarrhea worse, while still eating enough to support recovery.
Hydration matters more than food during a bout of diarrhea. Every loose stool pulls water and electrolytes out of your body. Drinking water alone isn’t enough if you’re losing fluids rapidly. Oral rehydration solutions, diluted fruit juice, or broth help replace both water and the salts your body is losing. Signs of dehydration to watch for include excessive thirst, dry mouth, dark urine, dizziness, and weakness.
Do Probiotics Actually Help?
Probiotics are widely recommended for diarrhea, but the evidence is weaker than most people assume. A large Cochrane review, which is considered the gold standard for evaluating medical research, found that probiotics probably make little or no difference in how long diarrhea lasts or how many people still have symptoms after 48 hours. Earlier reviews had been more optimistic, but those conclusions were largely driven by small studies. When researchers accounted for publication bias (the tendency for small positive studies to get published while negative ones don’t), the benefit largely disappeared.
That doesn’t mean probiotics are useless for gut health in general. But if you’re looking for something to stop diarrhea right now, they’re unlikely to be the answer.
Traveler’s Diarrhea May Need Antibiotics
If your diarrhea started during or shortly after international travel, the rules change. Mild cases that don’t interfere with your activities can be managed with loperamide and fluids alone. But moderate cases that disrupt your plans, or severe cases that leave you unable to function, often benefit from antibiotics.
For moderate traveler’s diarrhea, a doctor may prescribe a short course of antibiotics. For severe cases, especially those involving fever or bloody stool, antibiotics are strongly recommended. The specific prescription depends on where you traveled, since bacterial resistance patterns vary by region. Your doctor will choose the right option based on your destination and symptoms.
Preventive antibiotics before travel are not recommended for most people. The CDC reserves that approach for travelers with compromised immune systems or serious medical conditions.
Treating Diarrhea in Children
Children need a completely different approach. Anti-diarrheal medications like loperamide are not recommended for infants and children. Loperamide in particular can cause dangerous side effects in young kids, including severe abdominal swelling, extreme drowsiness, and in rare cases, life-threatening complications. Bismuth subsalicylate carries its own risks in children under 12 due to the aspirin-related compound.
For kids, the priority is hydration. Oral rehydration solutions are the cornerstone of treatment. Continue offering age-appropriate foods as tolerated, since restricting food doesn’t speed recovery. If a child’s diarrhea doesn’t improve within 24 hours, or if you notice no wet diapers for three or more hours, a fever above 102°F, bloody or black stools, or signs like a dry mouth, no tears when crying, or unusual sleepiness, those warrant prompt medical attention.
When Diarrhea Signals Something More Serious
Most diarrhea resolves on its own within a few days. But certain symptoms indicate you’re dealing with more than a passing stomach bug. For adults, diarrhea lasting more than two days without any improvement, black or bloody stools, a fever above 102°F, or signs of dehydration like very dark urine and dizziness all warrant a call to your doctor. These can point to bacterial infections, inflammatory conditions, or other problems that won’t respond to over-the-counter treatments alone.