**Core Concept**
Cocket and Dodd's operation is a surgical procedure used to manage a common condition affecting the gastrointestinal tract. This operation involves a specific type of anastomosis, which is a surgical connection between two structures. The procedure is named after the surgeons who first described it.

**Why the Correct Answer is Right**
Cocket and Dodd's operation is specifically designed to treat pyloric stenosis, a condition characterized by the narrowing of the pyloric channel in the stomach. This narrowing prevents the normal passage of food into the small intestine, leading to symptoms such as projectile vomiting. The operation involves creating a new opening between the stomach and the duodenum (the first part of the small intestine) to bypass the narrowed pyloric channel. This allows food to pass through the new opening and into the small intestine, alleviating symptoms.

**Why Each Wrong Option is Incorrect**
**Option A:** This is incorrect because Cocket and Dodd's operation is not used to treat appendicitis. While appendicitis may require surgical intervention, the specific procedure of Cocket and Dodd is not relevant to this condition.

**Option B:** This is incorrect because Cocket and Dodd's operation is not used to treat hiatal hernia. While hiatal hernia may require surgical repair, the procedure of Cocket and Dodd is not relevant to this condition.

**Option C:** This is incorrect because Cocket and Dodd's operation is not used to treat intestinal obstruction. While intestinal obstruction may require surgical intervention, the specific procedure of Cocket and Dodd is not relevant to this condition.

**Clinical Pearl / High-Yield Fact**
Cocket and Dodd's operation is a classic example of a surgical procedure that involves creating a new anastomosis to alleviate symptoms caused by a narrowed pyloric channel. This operation is a key concept in surgical gastroenterology and is essential to know for postgraduate medical students.

**Correct Answer: C. Pyloric stenosis**