Dairy sensitivity, lactose malabsorption, and elimination diets in inflammatory bowel disease.

The ability of inflammatory bowel disease (IBD) patients to tolerate dairy products and the guidance they receive from physicians and nutritionists on this subject are important considerations in the management of their IBD. Although most affected persons are able to consume a glass of milk daily without discomfort, additional consideration must be given to specific factors that can be relevant to certain individuals. The declaration by patients that they are "dairy sensitive" may be related to lactose intolerance or malabsorption, the long-chain triacylglycerol content of milk, allergy to milk proteins, as well as psychologic factors and the misconception that dairy products can be detrimental to their health. The prevalence of lactose malabsorption is significantly greater in patients with Crohn disease involving the small bowel than it is in patients with Crohn disease involving the colon or ulcerative colitis. In the latter colonic conditions the prevalence of lactose malabsorption is mainly determined by ethnic risk, which is based on genetic factors. In addition, lactose malabsorption in Crohn disease of the small bowel may be determined by factors other than lactase enzyme activity, such as bacterial overgrowth and/or small bowel transit time. Physicians differ widely in the advice they give their patients: some dogmatically advise avoidance of dairy products when the diagnosis is made whereas others discount the possible role of dairy in the management of IBD. IBD patients avoid dairy products more than they would need to based on the prevalence of lactose malabsorption and/or milk intolerance, probably partly because of incorrect patient perceptions and arbitrary advice from physicians and authors of popular diet books. Adequate scientific and clinical information is now available to permit recommendations about the intake of dairy products for each IBD patient.