Condition Center: Diarrhea

Photo Illustration by Ava Cruz
Photo Illustration by Ava Cruz

This informational guide, part of POPSUGAR's Condition Center, lays out the realities of this health concern: what it is, what it can look like, and strategies that medical experts say are proven to help. You should always consult your doctor regarding matters pertaining to your health and before starting any course of medical treatment.

Diarrhea is no one's favorite topic, but it's one of the more common medical conditions. In fact, most people experience diarrhea one or two times a year, and for some, it happens more often than that, the Cleveland Clinic reports. Whether you only deal with diarrhea a handful of times a year or it's a more pressing problem for you, there are ways to manage the symptoms and shorten the amount of time you're left sitting on the toilet in discomfort. But before you can start to treat diarrhea, it can be helpful to know what causes it.

Understanding Diarrhea

Diarrhea is characterized by loose, runny, and watery bowel movements, as well as needing to go more frequently, according to the Mayo Clinic. Needing to poop more than three times a day is typically a sign of diarrhea, says board-certified gastroenterologist Samantha Nazareth, MD, especially if you're usually a once-a-day type. A number of conditions and infections can cause diarrhea (we'll get to those in a second), but regardless of the underlying source, the mechanics behind the condition remain largely the same.

Here's what going on when your digestion is chugging along as it should: when you eat food, it passes from your mouth to your esophagus before it starts to get digested in your stomach, small intestine, and large intestine, or colon. "Normally, we have large volumes of water secreted into the small intestine, but most of this water is then absorbed before everything moves into the colon," Dr. Nazareth tells POPSUGAR. When you have diarrhea, however, one or more of the following happens, she says, leading to the runny, watery stool and frequent urges to "go" that characterizes diarrhea:

  • There's too much water content in your gut.
  • Your gut is unable to absorb the water.
  • Your gut is actually producing excess water, which can be caused by some medications and infections, including cholera and some types of E. coli.
  • Gut motility speeds up, which doesn't give your body enough time to absorb water before passing the stool.

Causes of Diarrhea

There are two types of diarrhea — acute and chronic. While the factors that cause each type all affect your gut's water absorption, production, or motility, acute and chronic diarrhea typically have different underlying sources. Acute diarrhea is temporary and lasts less than two weeks, according to the National Institutes of Health. "Usually, people describe this as acute gastroenteritis or a stomach bug," Dr. Nazareth says. She adds that most cases "are likely infectious in nature." Common causes of acute diarrhea include:

  • Viruses, such as rotavirus and norovirus.
  • Bacteria, including E. coli, salmonella, and C. difficile.
  • Parasites, such as Giardia and Cryptosporidium.

Chronic diarrhea, on the other hand, lasts more than four weeks. Causes of chronic diarrhea include:

  • Chronic infections that affect the gut (these infections might be caused by the same viruses or bacteria that can also cause acute diarrhea; if the bugs linger, so does the diarrhea).
  • Side effects from medications like antidepressants.
  • Problems digesting certain foods due to issues including lactose, fructose, or carbohydrate intolerance or celiac disease.
  • Diseases that harm the gut, such as inflammatory bowel disease (IBD) and small intestinal bacterial overgrowth (SIBO).

Most Effective Treatments For Diarrhea

The good news is that mild diarrhea can typically be managed at home, Dr. Nazareth says. If you're treating diarrhea at home, make sure to

  • Stay hydrated. Dehydration can be a side effect of diarrhea, so make sure you're drinking plenty of water.
  • Eat plain, low-fiber foods. You'll likely need to change your diet temporarily while getting over diarrhea, Dr. Nazareth says. Try to eat low-fat, low-fiber, dairy-free foods. She suggests foods like rice, roast beef, bananas, broths, and skinless chicken breasts.

Acute diarrhea typically goes away on its own, Dr. Nazareth says. However, if you've been experiencing symptoms for longer than two days without some improvement or if your symptoms are interfering with your daily life, Mayo Clinic advises that you see your doctor. You should also consult a doctor if you have or are experiencing any of the following:

  • Bloody or black stool
  • Severe abdominal or rectal pain
  • Fever
  • Dehydration (symptoms of dehydration include fatigue, dizziness, confusion, dark urine, or very little urine)
  • A suppressed immune system (signs include getting sick frequently or having issues like anemia, according to Mayo Clinic)

At the doctor's office, you may be prescribed an antibiotic or antiparasitic medication, depending on the cause of the diarrhea. Over-the-counter medications like loperamide (Imodium) or bismuth subsalicylate (Pepto-Bismol) might also help, but Dr. Nazareth recommends talking to a doctor before you take any OTC meds. "Don't take these if you also have a fever or blood in the poop," she adds, "and don't take more than the label tells you."