Diarrhea
When you have diarrhea, your bowel movements (stools) are loose and watery. It’s very common and usually not serious.
Many people get diarrhea once or twice each year. It typically lasts two to three days, and you can treat it with over-the-counter medicines. Some people have diarrhea more often as part of irritable bowel syndrome or other conditions.
What Causes Diarrhea?
Usually, diarrhea is caused by a virus that infects the gut. Some people call it "intestinal flu" or "stomach flu."
Other causes include:
Alcohol abuse
Allergies to certain foods
Diabetes
Diseases of the intestines (such as Crohn's disease or ulcerative colitis)
Eating foods that upset the digestive system
Infection by bacteria (the cause of most types of food poisoning) or other organisms
Laxative abuse
Medications
Overactive thyroid (hyperthyroidism)
Radiation therapy
Running (Some people get “runner’s diarrhea” for reasons that aren’t clear)
Some cancers
Surgery on your digestive system
Trouble absorbing certain nutrients, also called “malabsorption”
Diarrhea may also follow constipation, especially for people who have irritable bowel syndrome.