Most cases of diarrhea clear up on their own within one to seven days, depending on the cause. Viral infections, the most common trigger, typically resolve in one to three days. Bacterial infections can take up to a week. If your symptoms have lasted longer than two weeks, that crosses into a different category that may need medical attention.
Timelines by Cause
The single biggest factor in how long your diarrhea will last is what’s causing it. Here’s what to expect for the most common culprits:
- Norovirus: The most common cause of stomach bugs in adults. Most people recover within one to three days, though you can still spread the virus for a few days after symptoms stop.
- Campylobacter: A bacterial infection usually picked up from undercooked poultry or contaminated water. Symptoms typically start two to five days after exposure and resolve within about a week.
- Salmonella and E. coli: Other common bacterial causes that follow a similar pattern, usually lasting three to seven days without treatment.
- Traveler’s diarrhea: Bacterial cases last three to seven days untreated. Viral cases are shorter, typically two to three days. Parasitic infections are the exception and can drag on for weeks or even months without treatment.
- Food intolerance or medication side effects: These usually improve within a day or two once you remove the trigger. Antibiotics are a frequent offender, and symptoms can persist until you finish the course.
When Diarrhea Lasts Longer Than Expected
Doctors classify diarrhea by how long it sticks around. Anything under two weeks is considered acute. Diarrhea lasting 14 days or longer is classified as persistent, and that’s the point where something beyond a simple infection may be going on. Persistent diarrhea can signal a parasitic infection, a food intolerance you haven’t identified, inflammatory bowel disease, or other digestive conditions that need evaluation.
Chronic diarrhea, lasting four weeks or more, almost always requires testing to identify the underlying cause. It won’t resolve on its own the way a stomach bug does.
How Long It Lasts in Children
Kids tend to have longer bouts than adults. Virus-related diarrhea in infants and toddlers typically lasts 5 to 14 days, and acute episodes can take up to two weeks to fully resolve. Their smaller bodies also lose fluids faster, which makes dehydration the primary concern.
Watch for these signs of dehydration in babies and young children: fewer than six wet diapers in 24 hours, unusual sleepiness or irritability, few or no tears when crying, and a sunken soft spot on the top of the head. Any of these warrants a call to your pediatrician. For infants under 12 months, premature babies, or children with other medical conditions, contact a doctor if diarrhea lasts more than a single day.
What Helps It Resolve Faster
You can’t dramatically speed up a viral infection, but a few things make a real difference in how quickly you bounce back.
Fluids first. Dehydration is what makes diarrhea dangerous, not the diarrhea itself. Water alone isn’t ideal because you’re losing electrolytes too. Oral rehydration solutions, diluted broths, or drinks with sodium and potassium help your body absorb water more efficiently. Sip steadily rather than gulping large amounts at once, especially if you’re also nauseous.
Eat as tolerated. The old advice to stick strictly to bananas, rice, applesauce, and toast (the BRAT diet) is outdated. The American Academy of Pediatrics no longer recommends it for children because it’s too restrictive and lacks enough nutrients to support gut recovery. Following it for more than 24 hours may actually slow things down. For adults, those bland foods are fine during the worst of it, but you should return to a normal diet as soon as you can tolerate it. Your gut needs protein, fiber, and a range of nutrients to heal.
Over-the-counter medications. Loperamide (the active ingredient in Imodol and similar products) slows gut motility and can shorten the time to your last unformed stool. It works faster and more effectively than bismuth subsalicylate (the pink liquid). These medications are reasonable for adults with mild, non-bloody diarrhea, but they’re not recommended for young children or when a bacterial infection with fever is suspected, since slowing the gut can trap the bacteria inside.
Probiotics. There’s solid evidence that certain probiotic strains can shorten diarrhea episodes, particularly in children. A large review of studies found probiotics reduced diarrhea duration by roughly one to two days on average. The strains with the strongest track record are Lactobacillus rhamnosus GG and Saccharomyces boulardii, especially for viral and antibiotic-related diarrhea. Results vary, and not every probiotic product on the shelf contains these specific strains, so check the label.
Antibiotics. These only help when the cause is bacterial, and even then they’re not always necessary since most bacterial diarrhea resolves on its own. When they are used, antibiotics typically shorten symptoms by one to two days. For traveler’s diarrhea in particular, carrying a prescribed antibiotic can be worthwhile if you’re in a high-risk region.
Signs You Shouldn’t Wait It Out
Most diarrhea is unpleasant but harmless. A few specific warning signs change that picture. For adults, contact a doctor if diarrhea lasts more than two days, you develop a high fever, you’re having six or more loose stools per day, you notice blood or pus in your stool, or you have severe abdominal or rectal pain. A change in mental state, like confusion or unusual lack of energy, and frequent vomiting are also red flags that suggest dehydration may be getting serious.
For children, the threshold is lower. Diarrhea lasting more than one day, any fever in infants, refusal to eat or drink for more than a few hours, or frequent loose stools all warrant a call to the doctor. Young children can dehydrate within hours, not days, so erring on the side of caution is appropriate.