Worldwide, there are approximately 1.7 billion cases of diarrhea every year, killing around 525,000 children below 5 years old.1 In the U.S., adults have at least one episode of diarrhea, while children get at least two bouts of this illness, annually.2 This is a very common ailment that can become serious, but you can help prevent it as long as you are aware of its causes.
Common Reasons for Having Diarrhea
Diarrhea happens because of three mechanisms:
• Undigested food or fluids move too quickly through the small intestine and colon without the opportunity for water to be removed from the foods
• Fluid is secreted excessively from the stomach or small intestine
• Water absorption isn’t facilitated properly in the distal small intestine and the colon
Any of these three events may cause a person to expel loose and watery stools. Ideally, bowel movements must yield semi-solid stools containing undigested foods, which are formed after your small intestine and your colon absorb the water from the foods that you eat.3 There are numerous reasons why these mechanisms occur, causing you to experience diarrhea, with the most common ones being:4
Gastrointestinal (GI) tract infections: This can be caused by bacteria, viruses and parasitic organisms. Acute diarrhea is frequently due to E. coli, Salmonella, Shigella and Campylobacter infection.5
These microbes usually spread through contaminated food and water, typically affecting areas where there is inadequate sanitation and poor hygiene.6
It can also develop because of inflammatory bowel disease (IBD), which includes Crohn’s disease and ulcerative colitis.
In some cases, excessive antibiotic intake may lead to a Clostridium difficile bacterial infection and trigger diarrhea.9
Certain foods: Some people have difficulty digesting particular foods. For example, a person with lactose intolerance may get diarrhea after consuming dairy products.10
Other foods that can cause diarrhea are gluten, wheat, and spicy or fatty foods.11
Stress: Just like your brain, the gut is home to nerves. In an article published in SELF, Dr. Kyle Staller, a gastroenterologist at the Massachusetts General Hospital, points out, “The brain can impact what’s going on in the gastrointestinal tract, and vice versa.”
Gut spasms may occur as well because of stress. According to California-based gastroenterologist Dr. Ashkan Farhadi, widespread spasms lead to frequent colon contraction, and ultimately cause the body to expel loose and watery stool.12
Coffee: Caffeinated drinks like coffee can cause diarrhea because of their laxative potential.13
Caffeine stimulates muscle contraction in the large intestines. Plus, coffee’s acidic nature also causes an increase in the production of bile acids in the liver.
Although bile is stored in the gall bladder, coffee can prompt the organ to release bile in the intestines and cause diarrhea.14
Decaffeinated drinks are not a good option either. As the International Foundation for Functional Gastrointestinal Disorders reiterates, some chemicals in decaffeinated drinks may cause your stools to loosen too.15
Diarrhea May Also Occur Because of These Unusual Causes
You can also have diarrhea because of uncommon causes, such as:
• Intense exercise or “runner’s trots”: After an extensive workout, blood supply may be transferred from the digestive tract to your muscles, such as your leg muscles. This causes cramps and diarrhea. VeryWell Fit also highlights that other conditions such as irritable bowel disease, dehydration and lactose intolerance may increase exercise’s effects and raise your diarrhea risk.16
• Alcohol: It’s possible to experience diarrhea after drinking alcohol. When alcoholic beverages enter your system, they may trigger gastrointestinal tract inflammation, increased acid production, dehydration, faster digestion and colon contraction, and diarrhea.17
Although some causes of diarrhea are unavoidable, there are others that you can stay away from. For instance, you can avoid the use of antibiotics, unless absolutely necessary, because they kill both good and bad bacteria in the colon, which can cause diarrhea.18 Most GI infections can also be prevented through simple measures like washing your hands thoroughly, especially before eating and after using the bathroom.19