Although bleeding per rectum is a common complaint among children seeking care at an emergency department (ED), the bleeding is often limited. In general, the differential diagnosis of hematochezia can be divided into conditions causing painful versus painless rectal bleeding. Large volume, painless rectal bleeding suggests a specific, localizable lesion. The most common causes of such painless rectal bleeding in children are Meckel’s diverticulum and colonic juvenile polyps.

Meckel’s diverticulum is a persistent remnant of the omphalomesenteric duct that is seen in 2% of the population.¹ A typical Meckel’s diverticulum is approximately 2 inches (5 cm) long and is located on the antimesenteric border of the ileum, most commonly within 2 feet (approximately 60 cm) of the ileocecal valve, and thus is usually located in the right lower quadrant. More than 60% of patients who develop symptoms are younger than 2 years of age, and there are two types of mucosa, gastric and pancreatic, seen in the diverticulum. These findings of Meckel’s diverticulum are commonly referred to as the “rule of twos.”

Approximately 4% to 35% of affected individuals experience symptoms associated with Meckel’s diverticulum.² The most common presentation in children younger than age 4 is painless rectal bleeding secondary to acid secretion of functional ectopic gastric mucosa. This results in ulceration of the adjacent ileal mucosa and bleeding, which may present as hematochezia, or less commonly, as melena, and can be episodic and sometimes massive. Less frequent presentations include Meckel’s diverticulitis (which can mimic appendicitis), intestinal obstruction from intussusception, herniation of bowel through a patent omphalomesenteric fistula, or volvulus of bowel around a fibrous omphalomesenteric remnant attachment, the abdominal wall, and (rarely) perforation from an ingested foreign body trapped in the diverticulum.^3–6