Most diarrhea clears up within a few days. How to avoid dehydration, when loperamide helps – and when not to take it – and the warning signs that need a doctor.
What causes diarrhea?
Diarrhea means loose, watery stools three or more times a day. Short-term (acute) diarrhea, lasting a few days, is usually caused by:
- Viruses – norovirus is the most common cause of stomach bugs in the US
- Bacteria in contaminated food or water, such as Salmonella, E. coli or Campylobacter
- Parasites, such as Giardia from untreated water
- Medicines, especially antibiotics, and also metformin and antacids that contain magnesium
- Food intolerances, such as lactose (milk sugar) or sugar-free sweeteners like sorbitol
Diarrhea that lasts more than 4 weeks is called chronic diarrhea. It can be caused by conditions such as irritable bowel syndrome, inflammatory bowel disease or celiac disease, and needs a doctor's assessment.
The most important thing: avoid dehydration
Diarrhea makes you lose water and salts quickly. Drink plenty of fluids – water, broth and oral rehydration solutions, which replace salts as well as water. Avoid alcohol, and limit coffee and very sugary drinks, which can make diarrhea worse.
Signs of dehydration:
- Thirst and a dry mouth
- Dark urine, or urinating less than usual
- Feeling dizzy or lightheaded, especially when you stand up
- Tiredness
Eat when you feel able to. Bland foods such as bananas, rice, toast, crackers and soup are easy on the stomach. Fatty, fried and spicy foods – and for some people, dairy – can make things worse for a few days.
Loperamide: when it helps, and when not to take it
Loperamide slows down the gut, so you have fewer loose stools. It's useful for adults with watery diarrhea, including travelers' diarrhea – for example when you need to travel or work.
- Follow the label: for adults, 2 caplets after the first loose stool, then 1 after each further loose stool, and no more than 4 caplets in 24 hours.
- Stop and see a doctor if diarrhea lasts more than 2 days.
- Don't use it if you have bloody or black stools, and ask a doctor first if you have a fever or mucus in your stool. In these cases, slowing the gut can keep an infection inside longer.
- Never take more than the label says. High doses of loperamide can cause serious heart rhythm problems.
Antibiotics are only needed for certain bacterial or parasite infections. A doctor will decide, sometimes after testing a stool sample.
When to see a doctor
See a doctor if:
- Diarrhea lasts more than 2 days
- You have signs of dehydration
- You have a fever of 102°F (38.9°C) or higher
- You have severe pain in your belly or rectum
- Your stools are bloody or black and tarry
- Diarrhea started during or after a course of antibiotics or a hospital stay
- You've recently traveled abroad
- You're pregnant, over 65, or have a weakened immune system
Get urgent care if you can't keep any fluids down, are urinating very little or not at all, feel confused or faint, or have a racing heart.