High-Yield Concepts in Intestinal Obstruction (Gastrointestinal Diseases)

Question 1

Main differentials for Acute Intestinal Obstruction

Answer 1

Adynamic Ileus

Primary Intestinal Pseudo-Obstruction

Question 2

Most common cause of Small-Intestinal Obstruction

Answer 2

Adhesions

Question 3

Most common cause of Colonic Obstruction

Answer 3

Colon cancer

Question 4

Most irritating substances to the peritoneum

Answer 4

Hydrochloric acid, coloric contents, and pancreatic enzymes

Question 5

Hallmark of all forms of Intestinal Obstruction

Answer 5

Abdominal distention (more prominent in more distal sites of obstruction)

Question 6

Pathognomonic signs for Small-Bowel Obstructionon plain abdominal film

Answer 6

Fluid- and gas-filled loops of small intestine
“Stepladder” pattern with air-fluid levels
Absence or paucity of colonic gas

Question 7

Most commonly used modality to evaluate postoperative patients for Intestinal Obstruction

Answer 7

Abdominal CT (can differentiate between adynamic ileus, partial obstruction, and complete obstruction)

Question 8

Cecal diameter that increases likelihood of perforation

Answer 8

> 10 cm on plain abdominal film

Question 9

Most feared complication of Acute Intestinal Obstruction

Answer 9

Closed loop: lumen is occluded at two points by a single mechanism (such as a fascial hernia or adhesive band), also often with occlusion of blood supply, leading to high pressures and gangrene