Most cases of acute diarrhea resolve on their own within two to three days, but you can speed things along and feel better faster with the right combination of fluids, food choices, and over-the-counter treatments. The priority, in order: stay hydrated, eat the right things, and use medication when appropriate.
Hydration Comes First
Diarrhea pulls water and electrolytes out of your body fast. Replacing them is the single most important thing you can do, even before thinking about medication. Plain water helps, but it doesn’t replace the sodium and potassium you’re losing. An oral rehydration solution (ORS) does both at once.
You can buy premade ORS packets at most pharmacies, or make your own at home using the World Health Organization’s formula: half a teaspoon of salt, a quarter teaspoon of salt substitute (like No Salt), half a teaspoon of baking soda, and two tablespoons of sugar, all mixed into one liter (about four cups) of clean water. Sip it steadily throughout the day rather than drinking large amounts at once, which can trigger nausea.
For children, the amounts matter more precisely. Kids under 22 pounds (10 kg) need about 2 to 4 ounces of ORS after each watery stool. Kids over that weight need 4 to 8 ounces per episode. Infants should continue breastfeeding or formula feeding alongside ORS.
What to Eat (and What to Skip)
You may have heard of the BRAT diet (bananas, rice, applesauce, toast), but most experts, including the National Institute of Diabetes and Digestive and Kidney Diseases, no longer recommend restricting your diet that strictly. Once you feel like eating, you can return to your normal diet in most cases. Children with acute diarrhea should continue eating their usual age-appropriate foods.
That said, some foods genuinely help firm things up. Soluble fiber absorbs water in the gut and adds bulk to loose stool. Good sources include oats, bananas, applesauce, white rice, carrots, and barley. Meanwhile, avoid anything likely to make things worse: caffeine, alcohol, dairy (if you’re sensitive), greasy or fried foods, and sugar-heavy drinks like juice or soda, which can pull more water into the intestines.
Over-the-Counter Medications
Two common options are available without a prescription, and they work differently.
Loperamide (the active ingredient in Imodium) slows down intestinal movement, giving your gut more time to absorb water. The standard adult dose is two caplets (4 mg) after the first loose stool, then one caplet (2 mg) after each subsequent loose stool. The over-the-counter maximum is four tablets (8 mg) in 24 hours. If your doctor is involved, the prescription ceiling is higher, up to eight capsules (16 mg) per day, but don’t exceed the package directions on your own.
Bismuth subsalicylate (the active ingredient in Pepto-Bismol) coats the stomach lining and reduces inflammation in the gut. For adults and teenagers, the dose is two tablets every 30 minutes to one hour as needed, up to 16 tablets in 24 hours. It’s not recommended for children under 12.
When Not to Use Anti-Diarrheal Medication
Loperamide should not be used if your diarrhea comes with blood in the stool or a high fever. These signs suggest a bacterial infection (from organisms like Salmonella, Shigella, or Campylobacter), and slowing your gut down can actually trap the bacteria inside, making things worse. The same applies if you’re taking antibiotics and develop diarrhea, which could indicate a secondary infection that needs different treatment. In these situations, let the diarrhea run its course and focus on hydration while seeking medical advice.
Probiotics Can Shorten Recovery
Certain probiotic strains help your gut flora recover and can reduce how long diarrhea lasts. The best-studied strain for acute diarrhea is Saccharomyces boulardii, a beneficial yeast available over the counter. In a study of 160 children with acute diarrhea, those given S. boulardii had a median diarrhea duration of 3 days compared to 4 days in the group that didn’t receive it, along with fewer daily stools (1.7 versus 2.5). Results in adults are similar, though less extensively studied. Look for it by name on the label, as not all probiotic products contain it.
Zinc for Children
The World Health Organization recommends zinc supplementation for children with diarrhea: 20 mg per day for 10 to 14 days (10 mg per day for infants under six months). Zinc has been shown to reduce both the duration and severity of diarrheal episodes and helps prevent recurrence in the weeks that follow. This recommendation is especially relevant in developing countries where zinc deficiency is common, but it’s worth knowing about for any child with prolonged symptoms.
Signs That Need Medical Attention
Most diarrhea is self-limiting, but certain symptoms signal something more serious. Contact a healthcare provider if you or someone you’re caring for:
- Has had diarrhea lasting more than 24 hours without improvement
- Has bloody or black stool
- Has a fever of 102°F or higher
- Cannot keep fluids down
- Is unusually sleepy, confused, or irritable (especially in children and older adults)
These can indicate severe dehydration or an infection that requires more than home treatment. Severe dehydration is a medical emergency, particularly in young children and elderly adults, where it can progress quickly.
A Practical Game Plan
For most episodes of acute diarrhea, the approach looks like this: start sipping an oral rehydration solution right away. Eat when you’re ready, favoring soluble fiber foods like oats, bananas, and rice. Take loperamide if you need symptom relief and don’t have a fever or bloody stool. Add a Saccharomyces boulardii probiotic to potentially shave a day off your recovery. And keep watching your urine color: pale yellow means you’re hydrated enough, dark yellow or amber means you need more fluids.