Are your tummy troubles all in your head? Yes. And no. There’s a reason why, when you’re upset, you feel a knot in the pit of your stomach. “The brain and the digestive tract share many of the same nerve connections,” says Douglas A. Drossman, M.D., a gastroenterologist and psychiatrist and co-director of the University of North Carolina Center for Functional GI and Motility Disorders in Chapel Hill. It’s because, in the womb, the nerves that eventually separate into the brain, spinal cord and nerves of the intestine all have the same beginnings and remain interconnected.
Mental stress delivers a one-two punch to our digestive systems. First it causes the release of cortisol and adrenaline, hormones that not only divert energy to your muscles (so you can fight—or flee!), but also slow digestion. For momentary bouts of stress, that’s a good thing (you want to use your energy to escape the bear, not digest your lunch), but when stress is chronic those same hormones can make your digestive system sluggish, leading to constipation. In addition, chronic stress can alter the release of neurotransmitters like serotonin, which promotes relaxation. And because 80 percent of your body’s serotonin is located in your gut, it’s no wonder that when too much is released it can keep you running to the bathroom, while too little can make you irregular.Next: Foods to Get Your Stomach Back on Track »