A 10 month old infant presents with acute intestinal obstruction. Contrast enema X-ray shows the intussusceptions, Likely cause is
First, I need to recall what intussusception is. It's when a part of the intestine folds into itself, like a telescope. Common in children, especially under age 2. The leading cause in infants is often a lymphoid hyperplasia or a Meckel's diverticulum. But wait, the most common cause in this age group is usually a lead point, such as a Meckel's diverticulum, which can act as a point around which the intestine telescopes. However, in some cases, it's idiopathic. But in a 10-month-old, the most common associated condition is a Meckel's diverticulum. Alternatively, sometimes it's due to lymphoid hyperplasia, but I think Meckel's is more common here. Let me check the typical age. Meckel's is more common in younger children, up to 2 years. So the likely cause here would be a Meckel's diverticulum. The other options might include things like Hirschsprung's disease, but that's more associated with chronic constipation and megacolon. Volvulus is more in neonates. So the answer is Meckel's diverticulum.
**Core Concept** Intussusception occurs when a segment of the intestine telescopes into an adjacent segment, commonly in children under 2 years. The most frequent cause in this age group is a **Meckel's diverticulum**, a congenital remnant of the vitelline duct that acts as a lead point for intussusception.
**Why the Correct Answer is Right** A **Meckel's diverticulum** is a true diverticulum containing all layers of the intestinal wall, typically located 2 feet proximal to the ileocecal valve. Its presence creates a focal area of lymphoid hyperplasia or inflammation, leading to peristalsis that pulls the diverticulum into the adjacent bowel. This mechanical obstruction causes the classic "target sign" on contrast enema and acute intestinal obstruction symptoms in infants.
**Why Each Wrong Option is Incorrect**
**Option A:** *Hirschsprung's disease* involves aganglionosis of the colon, causing chronic constipation and megacolon, not acute intussusception.
**Option B:** *Volvulus* refers to twisting of the bowel around its mesentery, more common in neonates with malrotation.
**Option C:** *Lymphoid hyperplasia* can contribute to intussusception but is secondary to infections or inflammation, not a primary anatomic cause.
**Clinical Pearl / High-Yield Fact** Remember the "rule of 2s" for Meckel's diverticulum: affects **2% of the population**, presents before **2 years of age**, and is **2 feet from the ileocecal valve**. Always consider it as a lead point in pediatric intussusception.
**Correct Answer: C. Meckel's diverticulum**