If your bowels seem to go on the fritz every time a wave of stress hits, that’s no coincidence. Maybe a rough patch at work leaves you chained to the toilet with crampy, runny poops; or, on the flip side, you haven’t pooped in three days since that fight with a friend. Both stress diarrhea and stress constipation can be a thing for anyone—you don’t have to have a diagnosable gut disease or disorder, Megan Riehl, PsyD, clinical director of the Michigan Medicine GI Behavioral Health Program and co-author of Mind Your Gut, tells SELF.
That’s because of the brain-gut connection. There’s a reason you can feel stress in the pit of your stomach—your brain and gut talk back and forth nonstop, Kyle Staller, MD, MPH, director of the GI Motility Laboratory at Massachusetts General Hospital, tells SELF. “Your gastrointestinal tract has many nerves and is a nervous system organ, much like the brain,” he says. “The brain can impact what’s going on in the gastrointestinal tract, and vice versa.”
Having funky bowel movements can also be its own flavor of stress, Dr. Riehl points out, which only adds to the mental mayhem, threatening a vicious cycle. Below, experts break down why being stressed or anxious can set off such a chain reaction in the first place and share ways to break free—or prevent irregular stress poops entirely.
How can stress cause diarrhea, constipation, or both?
A bout of stress can prompt a slew of physical changes that can trickle into gut problems. To start, it clicks on your sympathetic nervous system (a.k.a. fight-or-flight) and readies you for action by “sending blood to your big muscles, directing it away from your GI system,” Kathryn N. Tomasino, PhD, associate professor of medicine and psychiatry and co-director of the Behavioral Medicine for Digestive Health program at Northwestern University Feinberg School of Medicine, tells SELF. “This can disrupt the normal rhythmic contractions of your bowels, causing stool to pass through more quickly or slowly,” she says. Poop flying through your system results in diarrhea, whereas a slowdown shows up as constipation.
At the same time, a surge of stress hormones like cortisol can alter the secretions in your gut and toss off the balance of your gut microbiome (the community of bacteria therein), Dr. Riehl says, which can also change the movements of your intestines. And all of this can mess with the crosstalk between the nerves in your gut and your brain, triggering gut spasms. Whether you get diarrhea or constipation depends on where those spasms occur and the location of stool in your intestines, Ashkan Farhadi, MD, director of MemorialCare Medical Group Digestive Disease Project in Fountain Valley, California, tells SELF.
