Figure 4From: Severe adult ileosigmoid intussusception prolapsing from the rectum: A case reportAlvine calculus and part of the intussusception. A submucosal lipoma located in the ileocecal junction (not shown) acts as the trigger of the intussusception, while the alvine calculus (black triangle) served as the exacerbating factor of the intussusception.Back to article page