Most cases of diarrhea clear up on their own within two to three days, but the right combination of fluids, food choices, and over-the-counter options can shorten that timeline and keep you comfortable. The priority is replacing lost fluids, then firming things up with diet and medication if needed.
Replace Fluids First
Diarrhea pulls water and electrolytes out of your body fast. Dehydration is the main risk, not the diarrhea itself. Plain water helps, but it doesn’t replace the sodium and potassium you’re losing with every trip to the bathroom.
Oral rehydration solutions are the gold standard. The formula recommended by the WHO uses equal parts sodium and glucose because that specific 1:1 ratio maximizes fluid absorption in your gut. You can buy pre-made rehydration packets at any pharmacy, or make a basic version at home with water, salt, and sugar. Broth, diluted fruit juice, and coconut water also work in a pinch. Sports drinks contain more sugar than ideal, but they’re better than nothing.
Sip steadily rather than gulping large amounts, which can trigger nausea. If you’re urinating less than usual, your mouth feels dry, or you feel lightheaded when standing, you’re already behind on fluids and need to increase your intake immediately.
Over-the-Counter Medications That Help
Two widely available options can slow things down. Loperamide (the active ingredient in Imodil) works by slowing the muscle contractions in your intestines, giving your body more time to absorb water from stool. It’s effective for garden-variety diarrhea from food, travel, or stress. Avoid it if you have a fever or bloody stools, since those suggest an infection your body needs to flush out.
Bismuth subsalicylate (Pepto-Bismol) takes a different approach. It reduces inflammation in your intestinal lining and has mild antibacterial properties. The standard adult dose is two tablets every 30 minutes to an hour as needed, up to 16 tablets in 24 hours. It can turn your tongue and stool black temporarily, which is harmless. Don’t give it to children under 12.
Eat the Right Foods
You don’t need to stop eating. In fact, continuing to eat helps your gut recover faster. The key is choosing foods that absorb excess water in your intestines rather than adding to the problem.
Soluble fiber is your best friend here. It dissolves in water and forms a gel-like material that slows digestion and adds bulk to loose stool. Good sources include oats, bananas, applesauce, white rice, and cooked carrots. These are the core of the classic BRAT diet (bananas, rice, applesauce, toast), which remains a reliable starting point even though it’s not as widely recommended as a strict protocol anymore.
Avoid foods that push things in the wrong direction: coffee, alcohol, dairy, greasy or fried foods, raw vegetables, and anything high in insoluble fiber like whole wheat bread, bran, or raw leafy greens. Insoluble fiber speeds up transit through your gut, which is the opposite of what you want right now. You can reintroduce these foods gradually once your stools firm up.
Probiotics Can Shorten Recovery
Certain probiotic strains help restore the balance of bacteria in your gut, which can reduce how long diarrhea lasts. The strain with the strongest evidence is Lactobacillus rhamnosus GG. In a controlled trial comparing it against another popular strain (Saccharomyces boulardii), LGG reduced the duration of acute diarrhea by roughly 19 hours and cut stool frequency by about 32% within two days. Saccharomyces boulardii showed smaller, less consistent benefits in that same study.
Look for supplements that list specific strains on the label rather than generic “probiotic blend” products. Yogurt with live active cultures can also help, though you’ll get a lower dose of beneficial bacteria compared to a targeted supplement.
What’s Actually Causing It
Understanding the cause helps you choose the right response. Diarrhea generally falls into two categories based on what’s happening inside your intestines.
The first type happens when something you ate or drank pulls extra water into your gut. Lactose intolerance is a classic example: undigested lactose sits in your intestines and draws fluid in. Sugar alcohols in sugar-free gum and candy do the same thing. This type stops when you stop eating the trigger food.
The second type is driven by infection. A virus, bacteria, or toxin irritates your intestinal lining and causes it to actively pump fluid into the gut. This is the kind you get from food poisoning or stomach bugs, and it continues regardless of whether you eat. It typically runs its course in one to three days for viral infections, though bacterial causes can last longer.
Diarrhea in Children
Kids dehydrate faster than adults, so fluid replacement is even more critical. Oral rehydration solutions designed for children (like Pedialyte) are the best option. Don’t use sports drinks, which have too much sugar and too little sodium for small bodies.
The WHO recommends zinc supplementation for children with diarrhea: 20 mg per day for 10 to 14 days, or 10 mg per day for infants under six months. Zinc has been shown to reduce both the severity and duration of episodes and helps prevent recurrence. This is particularly important in areas where zinc deficiency is common.
For children, seek medical attention if diarrhea doesn’t improve within 24 hours, if fever exceeds 102°F, or if stools are bloody or black.
Signs You Need Medical Help
Adults should see a doctor if diarrhea lasts more than two days without any improvement, if stools contain blood or appear black, or if fever reaches 102°F or higher. Severe diarrhea, defined as more than 10 bowel movements a day or fluid losses that clearly outpace what you’re able to drink, warrants prompt medical attention regardless of how long it’s been going on.