Most cases of acute diarrhea resolve on their own within three to seven days. The most important thing you can do in the meantime is replace lost fluids and electrolytes, eat the right foods, and avoid the ones that make things worse. Over-the-counter medications can also slow symptoms while your body fights off the underlying cause.
Fluids and Electrolytes Come First
Diarrhea pulls water and salts out of your body fast. Replacing them is the single most effective thing you can do, and plain water alone isn’t enough because it lacks the sodium, potassium, and sugar your intestines need to actually absorb the fluid. Commercial oral rehydration solutions like Pedialyte are designed for this, but you can make a simple version at home: mix half a teaspoon of salt and two tablespoons of sugar into about four cups of water. That ratio of sugar to salt mirrors the World Health Organization’s formula and helps your gut pull water back in efficiently.
If you don’t want to measure, there are easier options. Diluting regular Gatorade or Powerade (about one and a half cups mixed with two and a half cups of water plus half a teaspoon of salt) gets you close to the right electrolyte balance. Broth-based drinks work too: a regular-sodium bouillon cube dissolved in four cups of water with a quarter teaspoon of salt and two tablespoons of sugar. The key with all of these is sipping steadily throughout the day rather than gulping large amounts at once, which can trigger more cramping.
What to Eat (and What to Skip)
You may have heard of the BRAT diet: bananas, rice, applesauce, and toast. It’s been a go-to recommendation for decades, but major medical organizations including the American Academy of Pediatrics, the CDC, and the WHO no longer endorse it. The problem is that it’s too restrictive. It’s low in protein, fat, fiber, and several essential nutrients, and sticking to it for more than a day or two can actually slow recovery and worsen nutritional status. The old idea of “resting” the gut has been replaced by evidence showing that eating a normal, balanced diet as soon as you can tolerate it leads to shorter illness and less stool output.
That said, some foods genuinely make diarrhea worse. The biggest culprits are poorly absorbed sugars that draw extra water into your intestines:
- Sorbitol and other sugar alcohols: found in sugar-free gum, diet candies, and some “no sugar added” products. These accumulate in the colon and increase osmotic pressure, preventing water absorption.
- Excess fructose: apple juice is a common trigger, especially in children, because it contains more fructose than glucose. Pear juice and honey are high in fructose too.
- Lactose: even if you’re not normally lactose intolerant, a bout of diarrhea can temporarily damage the enzymes that break down dairy. Milk, ice cream, and soft cheeses are best avoided until you’ve recovered.
- Caffeine and alcohol: both stimulate intestinal contractions and increase fluid loss.
- Greasy or heavily spiced foods: these are harder to digest and can irritate an already inflamed gut lining.
Good choices while recovering include cooked vegetables, lean proteins like chicken or fish, eggs, oatmeal, potatoes, and bread. The goal is a reasonably varied diet, not a punishingly bland one.
Over-the-Counter Medications
Two medications are widely available without a prescription. They work in different ways, and choosing the right one depends on what’s going on.
Loperamide (sold as Imodium) slows the muscle contractions in your intestines, giving your body more time to absorb water. It’s effective for non-specific acute diarrhea at a daily limit of 8 mg for adults, which typically means two capsules initially and one after each loose stool. It works quickly, often within an hour, and is useful when you need symptom control for travel or work. However, you should avoid it if you have a high fever or bloody stools, since in those cases slowing the gut down can trap a bacterial infection inside.
Bismuth subsalicylate (Pepto-Bismol) takes a different approach. It reduces inflammation in the intestinal lining and has mild antibacterial properties. It’s gentler than loperamide and can also help with the nausea and cramping that often accompany diarrhea. It may turn your tongue and stool black temporarily, which is harmless. People who are allergic to aspirin or taking blood thinners should avoid it, since it contains a compound related to aspirin.
Probiotics That Actually Help
Not all probiotics are equally useful for diarrhea. The strain with the strongest evidence is Lactobacillus rhamnosus GG, which reduced the duration of acute diarrhea by about 19 hours in a randomized controlled trial comparing it to standard treatment alone. Saccharomyces boulardii, a beneficial yeast often recommended for diarrhea, did not show a statistically significant reduction in the same study, though other research has found it helpful for antibiotic-associated diarrhea specifically.
If you’re going to try a probiotic, look for the specific strain name on the label rather than just the genus. Start taking it as early in the illness as possible, since the benefit comes from shortening the overall course rather than stopping symptoms immediately. Yogurt with live cultures can contribute some beneficial bacteria, but the concentrations in supplement form are typically much higher.
Children Need a Different Approach
Kids dehydrate faster than adults, and the warning signs look different. In a child, watch for no wet diaper in three or more hours, crying without tears, a sunken appearance around the eyes or cheeks, unusual sleepiness or irritability, and skin that stays “tented” when you pinch and release it. If diarrhea in a child doesn’t improve within 24 hours, that warrants medical attention, compared to the two-day threshold for adults.
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 helps restore the intestinal lining and has been shown to reduce both the severity and duration of episodes. This recommendation applies primarily in settings where zinc deficiency is common, but it’s worth discussing with a pediatrician. Loperamide is not recommended for young children.
How Long Diarrhea Typically Lasts
Infectious diarrhea, the most common kind, usually starts 12 hours to four days after exposure to contaminated food or water and clears up within three to seven days. Viral causes (like norovirus or rotavirus) tend to resolve on the shorter end. Bacterial infections can take longer and are more likely to cause fever and bloody stool.
If your diarrhea lasts more than two days without any improvement, or if you notice blood or black color in your stool, a fever above 102°F, severe abdominal pain, or signs of dehydration like dark urine, dizziness, dry mouth, and extreme thirst, those are signals that something beyond a routine stomach bug may be happening and you need medical evaluation.