- Crohn's disease: this is a disease that affects any part of the gut and involves all the different layers of the bowel wall.
- Ulcerative colitis: which is a disease that affects the large bowel (colon) primarily and its lesions involve only the surface of the bowel wall (superficial mucosal inflammation).
Table 1: Summarizing the main differences between these two diseases
Ulcerative "procto" - Colitis |
Chron's disease |
Ulcerative hence superficial | deep (transmural) |
Superficial hence crypt abscesses & pseudopolyps | Deep with lymphocytic infiltrate |
No skip lesions | Skip lesions hence cobble stone appearance |
Starts at the rectum then involves the colon | Most commonly found in the terminal ileum. Can affect any area from mouth to anus. |
Rectal involvement hence dysentery is most common presentation | |
Risk of cancer |