Stress And Your Gastrointestinal Tract
Stress can influence health both directly and indirectly. Directly, stress exerts a powerful effect on all body systems by affecting the nervous system and the endocrine system. All gastrointestinal functions, such as appetite, digestion, muscle contractions in the intestine (motility) and defecation are mediated by nerve impulses and hormone signals. Stress can alter these signals, disrupting normal bowel functioning. Laboratory studies have shown that levels of psychological stress in the body can affect GI motility, but you don't need scientific research to know this if you've ever experienced a stomachache, diarrhea or loss of appetite in response to stress. Indirectly, stress can lead to an increase in harmful activities, such as smoking or drinking alcohol. Specific disorders involving the gastrointestinal system that are affected by stress include:
Constipation Or Diarrhea
There are several ways a stressful life or busy schedule can result in constipation. Since your nervous system controls your bowel motility, stress can alter normal movements of the colon. For some people, this can result in more frequent bowel movements, causing diarrhea. In others, it can result in infrequent bowel movements and increased water absorption from the stool, resulting in harder stools that are more difficult to pass. Constipation also can result if you are so busy that you disregard urges to have a bowel movement. Urges occur when the colon contracts strongly and passing stool at a time when an urge is not present can be more difficult. Finally, many medications that treat anxiety or depression can cause constipation or diarrhea as a side effect. Both diarrhea and constipation can be accompanied by abdominal cramps, and constipation may be accompanied by nausea.
While stress does not directly cause heartburn, it does foster behaviors that can lead to it. Eating too much, grabbing coffee and orange juice as you run out the door and eating late at night eating more fatty foods than usual, drinking alcohol and smoking all can promote gastroesophageal reflux disease (GERD, or acid reflux). Eating on the run can promote the swallowing of air along with food, causing burping of air and acid after meals. Late-night meals can worsen nighttime symptoms of heartburn, since you lie down for sleep with a full stomach. Heartburn can in turn worsen stress, because it can contribute to sleep loss and fatigue.
Irritable Bowel Syndrome
People with irritable bowel syndrome (IBS) often have increased symptoms because of stress. Although the exact cause of irritable bowel syndrome has still not been defined, the nervous system may be the problem rather than the action of the intestines. The nerves in the intestines are more sensitive to stimulation. In addition, the pain centers in the brain are more easily turned on in people with IBS.
It is not surprising that depression, anxiety, and traumatic events are strongly associated with IBS. People with irritable bowel syndrome report a higher frequency of life-stress experiences than do people without the disorder. They also show greater bowel reactivity when exposed to stress.
In the past, stress was thought to be the primary cause of ulcers. Today, doctors know that a stomach-lining infection from the Helicobacter pylori bacterium causes the majority of ulcers. Stress is now understood to play only a minor role. Very significant stress (such as a major medical illness) may encourage the development of an ulcer or interfere with ulcer healing. Smoking increases your risk of developing an ulcer and slows the healing of ulcers that already are present.