ALTERED COLONIC ENVIRONMENT, A POSSIBLE PREDISPOSITION TO COLORECTAL-CANCER AND COLONIC INFLAMMATORY BOWEL-DISEASE - RATIONALE OF DIETARY MANIPULATION WITH EMPHASIS ON DISACCHARIDES

A recurrent theme in the schema of pathogenetic mechanisms attributed to colorectal cancer (CRC) and inflammatory bowel disease (IBD) is the interaction between genes and environment. Dietary and other environm ental factors, and lower intestinal flora and their chemical interacti ons occur in the pathogenesis of both. Events at the mucosal surface m ay be influenced by factors in the luminal environment and by contribu tions of the host. in addition, both forms of IBD-Crohn's disease (CD) and ulcerative colitis (UC) - have distinctive associated host events . Even within CD and UC, different clinical patterns and prognoses may have different specific host mechanisms. Some of the current putative pathogenetic processes in CRC and IBD are reviewed. Particular attent ion is given to hypotheses relating to the role of dietetic substances , mainly fibre and dairy products, and how they may affect disease for mation. It is argued that within the context of hypotheses proposed fo r possible beneficial effects df these two dietetic factors, CRC and I BD may be considered together. Further support is lent to arguments th at similar and additional hypothetical features ascribed to beneficial effects of fibre may be attributed to disaccharides, lactose and its derivatives, lactulose and lactitol.