Okay, let's tackle this question. The question is about why an ileal resection is done in an adult with intussusception. First, I need to recall the causes of intussusception in adults versus children. In children, intussusception is often idiopathic or due to a lead point like a lymph node. But in adults, it's more likely to have an underlying pathology, such as a tumor or polyp, acting as a lead point.

The options are missing, but the correct answer is probably related to a neoplastic cause. Let me think: if the intussusception is due to a tumor, then resecting the affected ileum would be necessary. So the core concept here is that adult intussusception is often secondary to a lead point, and resection is needed to remove the cause.

For the wrong options, common distractors might include things like Meckel's diverticulum (which is more common in children), volvulus, or other non-neoplastic causes. I need to explain why those are incorrect. Also, maybe a wrong option could be a benign cause like a Meckel's diverticulum, but in adults, it's less likely.

The clinical pearl here is that in adults, any intussusception should raise suspicion for a neoplasm, so imaging like CT scan is crucial before surgery to identify the lead point. The surgical approach would then be resection to remove the tumor or other pathology causing the intussusception.

So, putting it all together, the correct answer is the one that mentions a neoplasm or tumor as the cause, prompting the ileal resection.

**Core Concept**
Intussusception in adults is most commonly caused by a **lead point**, such as a **neoplasm** (adenocarcinoma, lymphoma) or **polyp**, which acts as a focal point for bowel telescoping. This differs from pediatric cases, where it's often idiopathic or due to lymphoid hyperplasia. Surgical resection is required to remove the underlying pathology and prevent recurrence.

**Why the Correct Answer is Right**
In adults, **ileal resection** is performed because **intussusception is rarely idiopathic** and typically secondary to a **malignant or benign tumor** (e.g., colonic adenocarcinoma, Meckel's diverticulum, or a lipoma). Resection removes the lead point and restores bowel continuity. For example, a **colonic adenocarcinoma** in the cecum can cause ileocecal intussusception, necessitating right hemicolectomy.

**Why Each Wrong Option is Incorrect**
**Option A:** *Meckel’s diverticulum* is a pediatric cause, not adults (incidence drops post-puberty).
**Option B:** *Volvulus* causes a different pathophysiology (twisting of the bowel) and requires detorsion, not resection.
**Option C:** *Lymphatic filariasis* is a rare cause of intussusception in tropical regions but is not a primary indication for ileal resection.
**Option D:** *Intestinal obstruction* is a consequence, not a cause, of intussusception.

**Clinical Pearl / High-Yield Fact**
**Adult int

✓ Correct Answer: C. Villous adenoma