Common site of regional enteritis is –

Crohn disease (Terminal ileitis or regional enteritis) Crohn disease (CD) is an inflammatory bowel disease (IBD) which is characterized by - Sharply delimited and typically transmural involvement of the bowel by an inflammatory process with mucosal damage. The presence of non-caseating granulomas. Fissuring with the formation of a fistula. Any portion of intestine can be involved but most commonly small intestine is involved. Small intestine  → 40% Small intestine + colon  → 30% Colon → 30%