Inflammatory Bowel Diseases: Crohn's and Ulcerative Colitis
Start with the big picture
Crohn disease can affect any part of the gastrointestinal tract, commonly the terminal ileum and colon, and typically has patchy skip lesions with transmural inflammation. Ulcerative colitis is limited to the colon, starts at the rectum, and extends continuously; inflammation is generally confined to the mucosa and submucosa. Their characteristic findings also differ: Crohn disease may show cobblestoning, fistulas, and strictures, while ulcerative colitis may cause friable mucosa, pseudopolyps, and toxic megacolon. The deeper lesson connects these patterns with histology, imaging, laboratory markers, extraintestinal manifestations, cancer risk, and treatment approaches. Together, these comparisons provide a framework for distinguishing the diseases and understanding their complications.
What you'll learn
- Compare the distribution and depth of inflammation in Crohn disease and ulcerative colitis.
- Identify characteristic gross and histological findings in each disease.
- Relate major complications and extraintestinal manifestations to the disease patterns.
- Recognize selected imaging, laboratory, serological, and genetic associations.
- Summarize cancer-risk differences and the broad therapeutic approaches described.
Continue your study
Work through the complete notes and reinforce the topic with the study tools available in the full lesson.
