**Core Concept**
Gall stone ileus is a rare complication of gallstones where a gallstone migrates through a cholecysto-enteric fistula and enters the intestinal tract, causing small bowel obstruction.

**Why the Correct Answer is Right**
The patient's symptoms of colicky abdominal pain and hyper-peristaltic abdominal sounds suggest small bowel obstruction, which is a classic presentation of gall stone ileus. This condition occurs when a gallstone erodes through the gallbladder wall and enters the adjacent small intestine through a cholecysto-enteric fistula. The stone then causes obstruction of the small bowel, leading to the patient's symptoms.

**Why Each Wrong Option is Incorrect**
**Option B:** Hemobilia refers to the presence of blood in the bile, which can be a complication of liver or gallbladder disease, but it does not explain the patient's symptoms of colicky abdominal pain and hyper-peristaltic abdominal sounds.

**Option C:** Cholangitis is an infection of the bile ducts, which can cause abdominal pain, fever, and jaundice, but it does not typically present with small bowel obstruction symptoms.

**Option D:** Pneumobilia refers to the presence of air in the bile ducts, which can be seen on imaging studies, but it does not explain the patient's symptoms of colicky abdominal pain and hyper-peristaltic abdominal sounds.

**Clinical Pearl / High-Yield Fact**
Gall stone ileus is a surgical emergency that requires prompt diagnosis and treatment to prevent complications such as bowel ischemia and perforation. A high index of suspicion is required in patients with a history of gallstones and symptoms of small bowel obstruction.

**✓ Correct Answer: A. Gall stone ileus**