Inflammatory bowel disease: Part I. Clinical features and diagnosis

Familial and epidemiologic studies of inflammatory bowel disease indicate a strong genetic predisposition that is modified by certain environmental factors. Abnormal submucosal immune activation may be important in the etiology of the disease. Yersinia enterocolitica infection, various "gay bowel syndromes" and other recently described enteric infections often mimic Crohn's disease. An initial barium study is useful in documenting the extent of disease and complications. Endoscopic biopsy confirms the surface appearance and histologic features of inflammatory bowel disease. Newer photodocumentation techniques are expected to improve the comparability of endoscopic observations. Complications of inflammatory bowel disease occur frequently, may involve any organ system and may precede the onset of bowel symptoms.