You can have diarrhea every day from stress, says a GI doctor.

“Diarrhea results from a normal amount of feces mixed with a greater than normal amount of water,” begins David D. Clarke, MD, President, Psychophysiologic Disorders Association (, and Clinical Assistant Professor of Gastroenterology Emeritus, Oregon Health & Science University, Faculty Associate, Arizona State University.

Dr. Clarke continues, “When a person is experiencing stress-related diarrhea, the most likely cause is an increase in the propulsive muscle contractions of the large intestine (colon).”

The colon is actually a muscle, which is why it contracts (though it’s not the same type of muscle that enables you to move, which is skeletal muscle).

Dr. Clarke further explains that the increase in the colon’s propulsive contractions “decreases the amount of time that the colon can absorb water from the feces.

“It is possible for this to continue for as long as the stress is present.  This could be for weeks, months or even years.

“In people who suffer this condition for very long periods, the stress is often not fully recognized and often can be linked to adversity in childhood.

“Other causes of diarrhea that can persist for more than two weeks include losing the ability to digest milk sugar (lactose), intolerance of certain foods or medicines that you ingest daily, diseases that result in loss of the ability to absorb nutrients from the small intestine (such as sprue/celiac disease), inflammatory bowel diseases and chronic parasite infection.”

Do you have new-onset diarrhea every day and it seems to have coincided with new-onset stress? This happened to me.

The stress was enormous, and suddenly, I began having diarrhea—not just daily but multiple times a day and even overnight. And it looked funny, not like the usual diarrhea I’d had in my life.

As I was being prepped for a colonoscopy to find out what was going on, the nurse said that indeed, stress could be a cause, and that he himself had had stress diarrhea every day for three weeks as a result of his divorce.

The colonoscopy revealed that I had microscopic colitis, an inflammatory bowel disease, and to this day, I believe that the anxiety in my life had triggered it (though if you don’t have the gene for this benign condition, you can’t get it).

Since 1983 Dr. Clarke has successfully cared for over 7,000 patients with stress illness.
Lorra Garrick has been covering medical, fitness and cybersecurity topics for many years, having written thousands of articles for print magazines and websites, including as a ghostwriter. She’s also a former ACE-certified personal trainer.