 |  | Translated by Marta Campbell |
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01.12.2025 12:00 Uhr |
Intestinal problems can be caused by stress. / © Adobe Stock/fizkes
Excitement can cause diarrhea; ongoing problems at work or in the family can lead to stomach pain. Frequent nausea or heartburn may also be stress-related. But how exactly are psychological strain and digestion connected?
Why does stress affect an organ system so strongly when it largely functions autonomously? As a reminder: the digestive system is controlled by the enteric nervous system. It coordinates the digestive muscles and regulates the release of digestive secretions and nutrients. The brain is hardly involved in these processes.
Things change, however, when stressors act on the body. The brain then takes over central control and activates the »fight-or-flight« system. All bodily functions which are not immediately necessary for survival are reduced, and the focus shifts to an ideal supply of muscles and brain.
Whether it is a dangerous predator standing in front of us or an upcoming exam that makes us nervous — the brain does not distinguish between the two. It interprets both as acute stress and shuts down the digestive system.
More specifically: the sympathetic nervous system reduces the activity of the stomach and intestines, ensuring that no sensation of hunger arises. Mild nausea often accompanies this. The hypothalamus releases the hormone corticotropin-releasing factor (CRF). CRF inhibits stomach movements. Typical complaints that may arise now include stomach pain or heartburn. At the same time, CRF ensures that the large intestine empties as quickly as possible: intestinal movements increase and more water flows into the colon.
Although both systems are activated during acute stress, the inhibitory effect of the sympathetic nervous system is felt much faster than the hormone release by the hypothalamus. This explains why, in acute danger, digestive symptoms usually do not appear. But during foreseeable, upcoming challenges of modern life, persistent urges to defecate and/or diarrhea are among the most common and unpleasant stress symptoms.
