Stress feeling mentally or emotionally tense, troubled, angry, or overwhelmed stimulates colon spasms in people with IBS. The colon has a vast supply of nerves that connect it to the brain. These nerves control the normal rhythmic contractions of the colon and cause abdominal discomfort at stressful times. People often experience cramps or "butterflies" when they are nervous or upset. But with IBS, the colon can be overly responsive to even slight conflict or stress. Stress also makes the mind more tuned to the sensations that arise in the colon and makes the stressed person perceive these sensations as unpleasant. Some evidence suggests that IBS is affected by the immune system, which fights infection in the body. The immune system is also affected by stress. For all these reasons, stress management is an important part of treatment for IBS. Stress management comprises: stress reduction (relaxation) training and relaxation therapies, such as meditation. counseling and support. regular exercise, such as walking or yoga. changes to the stressful situations in your life. adequate sleep.