## **Core Concept**
The question describes a clinical scenario suggestive of a specific gastrointestinal condition characterized by recurrent abdominal pain, intestinal obstruction, and the passage of a mass per rectum. This presentation is highly indicative of an **intussusception**, a condition where a part of the intestine telescopes into another part, leading to bowel obstruction and potentially ischemia.

## **Why the Correct Answer is Right**
Intussusception is a condition that fits the described symptoms well. It is characterized by:
- **Recurrent abdominal pain**: Due to intermittent obstruction and ischemia of the bowel.
- **Intestinal obstruction**: Caused by the physical blockage of the intestine as one segment telescopes into another.
- **Passage of a mass per rectum**: This refers to the passage of the intussusceptum (the part of the intestine that is pushed into another part), which can sometimes be felt or seen as a mass coming out of the rectum.

## **Why Each Wrong Option is Incorrect**
- **Option A:** While certain conditions can cause abdominal pain and obstruction, they do not typically present with the passage of a mass per rectum as a characteristic feature.
- **Option B:** Similar to Option A, this condition might cause some of the symptoms but does not classically present with all three: recurrent pain, obstruction, and passage of a mass per rectum.
- **Option C:** This option might seem plausible but does not specifically match the combination of symptoms described, particularly the passage of a mass per rectum.

## **Clinical Pearl / High-Yield Fact**
A classic clinical pearl for intussusception, especially in pediatric patients, is the triad of **abdominal pain**, **vomiting**, and **blood in stool**. However, in adults, the presentation can be more variable and often includes a palpable mass. A key point to remember is that intussusception can be both a cause and a result of an underlying pathology, such as a tumor.

## **Correct Answer:** . Intussusception