Most cases of diarrhea in healthy adults resolve on their own within one to three days. While you wait, the right combination of fluids, food choices, and over-the-counter medication can slow things down significantly and keep you from getting dehydrated. Here’s what actually works.
Replace Fluids First
Diarrhea pulls water and electrolytes out of your body fast. Severe cases, meaning ten or more loose stools a day, can cause dehydration that becomes dangerous if fluid losses outpace what you’re drinking. Your first priority isn’t stopping the diarrhea itself. It’s replacing what you’re losing.
Water alone isn’t enough because you’re also losing sodium and potassium. Oral rehydration solutions (sold as Pedialyte or store-brand equivalents) are the most efficient option. Broth, diluted fruit juice, and sports drinks also work in a pinch. Sip steadily rather than gulping large amounts, which can trigger more cramping. If your urine is dark yellow or you feel dizzy when standing, you’re already behind on fluids.
Over-the-Counter Medications That Help
Two types of OTC medication are widely used for diarrhea, and they work differently.
Loperamide (sold as Imodium) slows the muscular contractions in your intestines, giving your gut more time to absorb water. It also tightens the anal sphincter, which helps with urgency. The standard adult dose is two caplets (4 mg) to start, then one caplet (2 mg) after each loose stool, up to a maximum of eight caplets (16 mg) in a day. For most people with a short bout of diarrhea, this is the fastest way to reduce the number of trips to the bathroom.
Bismuth subsalicylate (sold as Pepto-Bismol) takes a gentler approach, coating the intestinal lining and reducing inflammation. It’s a good choice for milder symptoms or when nausea is part of the picture. One important caution: it contains a compound related to aspirin, so anyone with aspirin sensitivity or who already takes aspirin-containing medications should avoid it. It should also not be given to children or teenagers recovering from the flu or chickenpox because of the risk of Reye’s syndrome, a rare but serious condition.
One situation where you should skip loperamide: if you have a high fever or bloody stools. Those suggest a bacterial infection, and slowing your gut down can make things worse by keeping the bacteria inside longer.
What to Eat (and What to Avoid)
You don’t need to starve yourself, but you do need to be selective. A low-fiber diet limits the bulk passing through your intestines and can noticeably reduce the frequency of bowel movements. Aim for foods with no more than 1 to 2 grams of fiber per serving.
Good options during active diarrhea include:
- White rice, white bread, saltine crackers, and plain pasta
- Bananas, applesauce, and canned peaches without skin
- Well-cooked potatoes, carrots, and green beans
- Eggs, plain chicken, fish, and tofu
- Creamy peanut butter (not chunky)
Foods to avoid until things settle down:
- Whole grains, brown rice, oatmeal, and anything with bran
- Raw fruits and vegetables, nuts, seeds, and dried fruit
- Beans, lentils, and peas
- Greasy or fried foods
- Coffee, alcohol, and carbonated drinks
Dairy is fine for some people but makes diarrhea worse if you’re lactose intolerant. Lactose intolerance can also temporarily flare up during a gut infection even if you normally tolerate milk, so consider cutting dairy for a few days if your symptoms aren’t improving.
Why You Have Diarrhea in the First Place
Understanding the cause helps you pick the right response. Diarrhea generally falls into a few categories based on what’s happening inside your intestines.
The most common type in otherwise healthy adults is triggered by a virus like norovirus. Your gut lining becomes inflamed and starts pushing food through faster than normal while also secreting extra fluid. This type tends to come on suddenly with nausea, cramping, and sometimes a low fever. It typically resolves within one to three days without any specific treatment beyond staying hydrated.
Another common pattern happens when your intestines can’t properly absorb something you ate. Lactose intolerance is the classic example: undigested lactose draws water into the bowel, creating loose, watery stools. Sugar alcohols found in sugar-free gum and candy (sorbitol, xylitol, mannitol) do the same thing. Fructose from fruit juice or honey can also be a culprit. If your diarrhea comes and goes and seems linked to specific foods, this pattern is worth investigating.
Less commonly, diarrhea can be driven by conditions that cause your intestines to actively secrete fluid. This type tends to produce higher volumes of watery stool, continues even when you stop eating, and often wakes you up at night. Causes range from bile acid problems (especially after gallbladder removal) to certain medications, thyroid disorders, and inflammatory bowel conditions like Crohn’s disease. Diarrhea that persists for more than a few weeks, especially with large-volume watery stools, points toward something in this category and warrants medical evaluation.
Probiotics May Shorten Recovery
Probiotics won’t stop diarrhea immediately, but certain strains can cut the duration. The best-studied option for acute diarrhea is Saccharomyces boulardii, a beneficial yeast available over the counter. A meta-analysis published in Pediatrics found it reduced diarrhea duration by roughly 20 hours compared to placebo. That’s meaningful when you’re on day two and miserable.
S. boulardii is available under brand names like Florastor. Other probiotic strains in the Lactobacillus family have some supporting evidence, but the data is strongest for S. boulardii specifically. Start taking it at the onset of symptoms for the best effect.
Signs Your Diarrhea Needs Medical Attention
Most diarrhea is uncomfortable but not dangerous. However, certain symptoms signal that something more serious may be going on:
- Diarrhea lasting more than two days without any improvement
- Blood or black color in your stools
- Fever above 102°F (39°C)
- Severe abdominal or rectal pain
- Signs of dehydration: excessive thirst, very dark urine, little or no urination, dizziness, or severe weakness
For children, the timeline is shorter. Diarrhea that doesn’t improve within 24 hours, no wet diaper in three or more hours, or unusual sleepiness or irritability all warrant a call to the pediatrician. A sunken appearance around the eyes, cheeks, or abdomen, or skin that stays “tented” when you pinch it, signals significant dehydration that needs prompt treatment.