The most important thing to take when you have diarrhea is fluid with electrolytes, not medication. Most acute diarrhea resolves on its own within a few days, and the real danger is dehydration. Over-the-counter medications like loperamide and bismuth subsalicylate can help manage symptoms, but replacing lost water and salts should be your first priority.
Fluids and Electrolytes Come First
Every loose stool pulls water, sodium, and potassium out of your body. Plain water alone doesn’t replace what you’re losing, which is why oral rehydration solutions work better than water by itself. You can buy premade electrolyte drinks or make your own at home: combine half a teaspoon of salt, a quarter teaspoon of salt substitute (potassium chloride), half a teaspoon of baking soda, and two tablespoons of sugar in one liter of water. The sugar isn’t just for taste. It helps your intestines absorb sodium and water more efficiently.
Sip steadily throughout the day rather than gulping large amounts at once. Signs that you’re getting dehydrated include dark urine, dry mouth, excessive thirst, dizziness, and lightheadedness. If you notice these, increase your fluid intake immediately.
Over-the-Counter Medications
Two OTC options are widely available: loperamide (sold as Imodium) and bismuth subsalicylate (sold as Pepto-Bismol). They work differently and suit different situations.
Loperamide slows the muscle contractions in your intestines, giving your gut more time to absorb water. It’s effective for reducing the frequency of loose stools and is the stronger of the two options. The standard daily limit for adults is 8 mg. Loperamide should not be used if you have a fever or bloody stools, since these suggest a bacterial infection where slowing your gut down could make things worse.
Bismuth subsalicylate works more gently. It reduces inflammation in your intestinal lining and has mild antibacterial properties. It’s a reasonable choice for milder symptoms or an upset stomach that comes with the diarrhea. Be aware that it can temporarily turn your tongue and stools black, which is harmless. Because it contains a compound related to aspirin, avoid it if you take blood thinners or are allergic to aspirin.
Probiotics That Shorten Recovery
Two probiotic strains have the strongest clinical evidence for diarrhea: Saccharomyces boulardii (a beneficial yeast) and Lactobacillus rhamnosus GG. Both have been shown to shorten the duration of acute infectious diarrhea by roughly one day. That may sound modest, but when you’re dealing with frequent watery stools, cutting a full day off recovery matters.
These probiotics are especially useful if your diarrhea is caused by antibiotics. Antibiotic-associated diarrhea affects roughly 17 to 22 percent of people taking antibiotics. In clinical trials, Saccharomyces boulardii cut that risk roughly in half, from about 17% to 8% in adults. Lactobacillus rhamnosus GG showed similar results, reducing the rate from about 22% to 12%. For the best effect, start the probiotic at the same time you begin the antibiotic course, and look for products providing at least 10 billion colony-forming units per day.
What to Eat and What to Avoid
You don’t need to follow a restrictive diet. Once you feel ready to eat, you can return to your normal meals in most cases. The old advice about sticking exclusively to bananas, rice, applesauce, and toast (the BRAT diet) isn’t strongly supported. Your body needs calories to recover.
What does matter is avoiding things that make diarrhea worse:
- Caffeine from coffee, tea, and sodas stimulates your intestines and can increase stool frequency.
- Alcohol irritates the gut lining and worsens dehydration.
- High-fat foods like fried foods, pizza, and fast food are harder to digest when your gut is inflamed.
- Dairy products containing lactose can be difficult to tolerate. Some people have trouble digesting lactose for up to a month after a bout of diarrhea, even if they normally handle dairy fine.
- Sugar alcohols found in sugar-free gum, candies, and some diet products pull water into the intestines and worsen loose stools.
- Fructose-heavy drinks like fruit juices and sweetened beverages can have the same effect.
When Antibiotics Are Needed
Most diarrhea is caused by viruses and doesn’t respond to antibiotics. Prescription treatment is reserved for moderate to severe bacterial diarrhea, particularly traveler’s diarrhea or cases involving fever and bloody stools. The CDC guidelines match treatment intensity to symptom severity: mild cases need only OTC remedies, moderate cases may warrant antibiotics, and severe or bloody diarrhea calls for antibiotic treatment.
If you’re traveling internationally and develop diarrhea that interferes with your plans, a doctor may prescribe a short course of antibiotics, sometimes as a single dose. For travel to Southeast Asia or regions with high rates of antibiotic-resistant bacteria, specific antibiotics are preferred over others. This is a situation where having a pre-travel consultation can pay off, since your doctor can prescribe a “just in case” supply before you leave.
Treating Diarrhea in Children
Children, especially infants, dehydrate faster than adults, making fluid replacement even more critical. Offer an oral rehydration solution in small, frequent sips. For children under 10 kg (about 22 pounds), give 2 to 4 ounces of rehydration solution after each watery stool. For children over 10 kg, give 4 to 8 ounces. A teaspoon or syringe works well for younger kids who resist drinking.
Infants should continue breastfeeding or formula feeding throughout the illness. Don’t dilute formula or switch to a special diet unless your pediatrician advises it. Children should return to their normal age-appropriate diet as soon as possible.
Anti-diarrheal medications like loperamide are not recommended for infants and young children. Side effects including drowsiness, nausea, and slowed gut function pose greater risks in small bodies. Probiotics, specifically Saccharomyces boulardii and Lactobacillus rhamnosus GG, have a better safety profile in children and are recommended by pediatric gastroenterology groups for acute gastroenteritis.
Warning Signs That Need Medical Attention
In adults, diarrhea lasting more than two days without improvement warrants a visit to your doctor. Seek care sooner if you develop a fever above 102°F (39°C), notice blood in your stool, or show signs of significant dehydration like very dark urine, severe weakness, or dizziness that doesn’t resolve with fluids.
For children, the timeline is shorter: get medical attention if diarrhea doesn’t improve within 24 hours. Other red flags in children include no wet diaper for three or more hours, a dry mouth or tongue, crying without tears, unusual sleepiness or irritability, and sunken eyes or cheeks. If you gently pinch the skin on a child’s hand and it doesn’t flatten back immediately, that’s a sign of significant dehydration that needs prompt care.