Meckel diverticulum

A Meckel's diverticulum, a true congenital diverticulum, is a slight bulge in the small intestine present at birth and a vestigial remnant of the omphalomesenteric duct (also called the vitelline duct or yolk stalk). It is the most common malformation of the gastrointestinal tract and is present in approximately 2% of the population, with males more frequently experiencing symptoms. It may contain ectopic acid–secreting gastric mucosa and/or pancreatic tissue. It can cause melena, right lower quadrant pain, intussusception, volvulus, or obstruction near the terminal ileum.