Meckel's diverticulum, gross specimen. This is a pouch (upper centre) protruding from the wall of the small intestine. It is a remnant of the umbilical cord. It is a common deformity, occurring in as many as 2% of the population. In most cases the diverticulum causes no problems, but it may lead to internal bleeding in children, and a blocked intestine in adults. The latter can cause severe abdominal pain, vomiting and swelling. If the diverticulum causes problems it can be surgically removed.