Question

A 60 year old obese female presents with abdominal pain, distension, and increased bowel sounds. There are multiple air fluid levels and air in the biliary tree on imaging. She also has a history of hysterectomy 2 years back. What is the probable diagnosis?

• A. Gall stone Ileus
• B. Small bowel obstruction
• C. Large bowel obstruction
• D. Paralytic ileus

Hint:

Look for Rigler's triad: small bowel obstruction + pneumobilia + ectopic gallstone -- a rare but classic cause of obstruction in elderly females.

Answer 1

The Correct Option is A

Diagnosis: Gallstone Ileus

The combination of small bowel obstruction + air in the biliary tree (pneumobilia) in an elderly obese woman is the hallmark of Gallstone Ileus.

Pathophysiology:
- Chronic cholecystitis leads to adhesion between the gallbladder and adjacent bowel (usually duodenum)
- A large gallstone (> 2.5 cm) erodes through the gallbladder wall into the bowel, creating a cholecystoenteric fistula
- The gallstone travels down the GI tract and becomes impacted, most commonly at the narrowest part -- the ileocaecal valve
- This causes mechanical small bowel obstruction
- Air enters the biliary tree through the fistula, causing pneumobilia on X-ray

Rigler's Triad (classic radiological triad):
1. Small bowel obstruction (multiple air-fluid levels)
2. Pneumobilia (air in biliary tree)
3. Ectopic radio-opaque gallstone (visible in only 15% of cases)

Differentiating from paralytic ileus:
- Paralytic ileus: absent bowel sounds, generalised gaseous distension of both small and large bowel
- Gallstone ileus: increased/high-pitched bowel sounds, localized small bowel obstruction pattern

Management: Enterolithotomy (remove the stone); cholecystectomy and fistula repair may be staged

\[\boxed{\text{Gallstone Ileus}}\]