Why does my stomach clench up in knots when I’m stressed?


Whenever I’m stressed out my stomach clenches up in knots. Why does it do that?


A particularly sad experience is described as “gut-wrenching.” Hearing about a gruesome crime makes you “feel nauseated.” An upcoming presentation gives you “butterflies in your stomach.” We use these expressions because anger, anxiety, sadness, elation and other emotions can trigger symptoms in our gastrointestinal tract.

The brain has a direct effect on the stomach. Even the thought of eating can release the stomach’s juices before food gets there. This connection goes both ways. A troubled gut can send signals to the brain, just as a troubled brain can send signals to the gut. Therefore, your distressed gut can be as much the cause as the product of anxiety, stress or depression.

Your brain and the gastrointestinal (GI) tract are intimately connected. The gut is controlled by the enteric nervous system (ENS), a complex system of about 100 million nerves that starts in the brain and ends in the gut. It controls every aspect of digestion, so it’s no surprise that when the brain is disturbed, the gut can be as well.

The nerve endings of the ENS are embedded in the gut wall. Those nerves not only send messages from the brain to the gut; they also send messages from the gut to the brain. There is a rich dialogue between gut and brain during the entire journey of food through the 30-foot-long digestive tract.

This two-way communication explains why you stop eating when you’re full. It’s because nerve cells in your gut let your brain know that your stomach has expanded. It also explains why anxiety over this morning’s exam has ruined your appetite for breakfast. The stress activates your “fight or flight” response, which inhibits secretion of stomach juices and reduces blood flow to your gut, as more blood is diverted from the stomach and into your muscles.

Emotions cause genuine chemical and physical responses in the body that can result in pain and discomfort. For example, stress can affect movement and contractions of the GI tract. The gut is a tube containing circular muscles that move food down your digestive system. Normally the muscles all work in a coordinated way, like oarsmen rowing a shell. When, instead, the muscles are not coordinated and start to fight each other, pain can result.

Stress also makes all parts of the body more vulnerable to both inflammation and infection. Inflammation and infection in the gut produce pain, gas, bleeding, nausea, diarrhea and other symptoms.

If ongoing stress is causing frequent GI problems for you, treatments such as cognitive behavioral therapy, relaxation techniques and hypnosis might help. These treatments can help reduce anxiety and encourage healthy behaviors to help you cope with pain and discomfort.