Does Stress Cause Ulcerative Colitis?

My son has ulcerative colitis. Could stress be responsible for his flare-ups?

The severity of symptoms in ulcerative colitis (a chronic inflammatory disease of the large intestine and rectum) can vary depending on the location of the inflammation within the bowel and the severity of the inflammation. Doctors do not know the exact cause of ulcerative colitis. Most researchers do not believe that psychological stress is the cause of ulcerative colitis.

Nevertheless, it is known that stress may worsen the symptoms of this condition. And, it is therefore, recommended that people with ulcerative colitis practice stress-control techniques, along with eating a healthy diet and exercising regularly, to help control the symptoms of the disease.