There were 15 (37.5%) patients with lesions involving the terminal ileum (L1), 11 (27.5%) colon (L2), 11 (27.5%) ileocolon (L3) and 3 (7.5%) upper gastrointestinal tract (L4).

• 病变部位位于末端回肠(L1)者15例(37.；5%25)；结肠(L2)11例(27