15. Distinguishing characteristics of CD and UC UC CD Feature Only colon (rarely “ backwash ileitis ” SB or colon Location Continuous, begins distally Skip lesions Anatomic distribution Involved in >90% Rectal spare Rectal involvement Universal Only 25% Gross bleeding Rare 75% Peri-anal disease No Yes Fistulization No 50-75% Granulomas
16. Endoscopic features of CD and UC UC CD Feature Continuous Discontinuous Mucosal involvement Rare Common Aphthous ulcers Abnormal Relatively normal Surrounding mucosa Rare Common Longitudinal ulcer No In severe cases Cobble stoning Common Uncommon Mucosal friability distorted Normal Vascular pattern
17. Pathologic features of CD and UC UC CD Feature Uncommon Yes Transmural inflammation No 50-75% Granulomas Rare Common Fissures No Common Fibrosis Uncommon Common Submucosal inflammation
18. Radiologic features of CD and UC UC CD Feature Collar button ulcers Nodularity granularity cobble stoning string sign of SB
19. Comparison of Features in Ulcerative Colitis and Crohn's Disease Crohn's Disease Ulcerative Colitis Feature Transmural Mucosal Depth of inflammation Skip areas Contiguous Pattern of disease Mouth to anus Colorectum Location Less common Usual Rectal involvement Common Backwash ileitis (15%–20% of patients ) Ileal disease Common Rare Fistulas Common Rare Perianal disease 10%–30% of patients Unlikely Granulomas Less common Usual Overt bleeding More common Unlikely Malnutrition Colorectal cancer, small bowel cancer (depending on disease location ) Colorectal cancer, cholangiocarcinoma (if primary sclerosing cholangitis is present ) Cancer risk Harmful Protective Tobacco use
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