1. Colonoscopy during an attack of severe ulcerative colitis is a safe procedure and of great value in clinical decision making;Alemayehu;Am J Gastroenterol,1991
2. Inflammatory bowel disease activity assessment using technetium-99m-HMPAO leukocytes;Arndt;Dig Dis Sci,1997
3. Development of a Crohn's disease activity index: National cooperative Crohn's disease study;Best;Gastroenterology,1976
4. Ulcerative colitis: I. Classification of types, clinical behavior, life history, prognosis;Bockus,1958
5. Depth of ulceration in acute colitis: Correlation with outcome and clinical and radiologic features;Buckell;Gastroenterology,1980