Endoscopic image of human small intestineA study appearing in the American Journal of Epidemiology (1990;132(6):1111-19) looked at the birth records of 257 patients with inflammatory bowel disease born between 1924 and 1957. They were compared to 514 healthy controls and matched by date of birth, sex and maternal age. Infections before or after delivery increased the risk for developing inflammatory bowel disease four-fold. Viral infections with fever were a particularly strong risk factor. Children with lower socioeconomic status also had a higher risk for developing inflammatory bowel disease. Breast feeding had no influence on the incidence of the disease. Some evidence also suggests a genetic susceptibility to the disease. Children exposed to adult smoking, or who had a mother who smoked during pregnancy, may have an increased risk for developing Crohn’s disease, but not ulcerative colitis. Research appearing in Gastroenterology (April 1992;102(4)) compared 39 patients with ulcerative colitis and 33 patients with Crohn’s disease to healthy controls and found a dose-dependent relationship to the exposure of cigarette smoke and the development of irritable bowel disease.