My stomach hurts when I'm stressed

The gut has its own nervous network — the enteric nervous system, with over a hundred million neurons — connected to the brain by the vagus nerve. Communication runs both ways, and most of the traffic goes up from the gut to the brain rather than down.

Under stress the body redirects blood to the muscles and slows digestion, because digestion is a long-term investment and the alarm system solves immediate problems. The result is nausea, a knotted feeling, cramps or an abrupt speeding of transit — normal physiological reactions, not signs of weakness.

The second layer is visceral hypersensitivity. Under chronic stress, the threshold at which gut sensations reach awareness drops. The same amount of gas or the same contraction that previously passed unnoticed becomes pain. This is not imagination — it is a real change in signal processing, measurable in the laboratory.

Irritable bowel syndrome works on exactly this mechanism, and being stress-linked does not make it less real: it is a medical diagnosis, with criteria and treatment.

• Exclude first, then work on the stress. A consultation and, if indicated, testing for Helicobacter or coeliac disease. The stress link stays valid afterwards; it simply stops hiding something else.
• Keep a double diary for two weeks. What you ate and what happened that day, side by side. The pattern usually emerges clearly and separates dietary from emotional better than memory does.
• Diaphragmatic breathing, five minutes, twice a day. Not during a flare — as training. Regular vagal stimulation lowers visceral sensitivity, and the effect accumulates.
• Don't avoid. Dropping events out of fear of the symptom gradually narrows life and strengthens the fear. Going with a plan — I know where the loo is, I can step out — beats staying away.
• Gut-directed hypnotherapy and CBT have solid evidence in irritable bowel syndrome, with effects comparable to drug interventions. Not an alternative to a doctor; part of the treatment.