Radiology · Year 4 · from Radiology

Case 1: Small Bowel Obstruction

Patient Demographics

  • Age: 62 years
  • Sex: Female

Chief Complaint

Abdominal pain, distension, and vomiting for 2 days

Presenting Symptoms

The patient presents with progressive crampy abdominal pain that began 2 days ago. She reports abdominal distension, nausea, and multiple episodes of bilious vomiting. She has not passed flatus or had a bowel movement in 36 hours. Her surgical history includes an open appendectomy 25 years ago and a cesarean section 30 years ago.

Physical Exam Findings

  • Vital Signs: BP 118/74 mmHg, HR 98 bpm, RR 18/min, Temp 37.2C
  • General: Uncomfortable appearing, lying still
  • Abdomen: Distended, tympanic to percussion, diffuse tenderness without peritoneal signs, high-pitched bowel sounds with occasional rushes, well-healed lower midline and McBurney's point scars
  • Rectal Exam: Empty rectal vault, no masses

Imaging Findings and Interpretation

Abdominal Radiograph (Supine and Upright):

  • Multiple dilated small bowel loops (>3 cm diameter)
  • Valvulae conniventes visible extending across the full lumen width
  • Multiple air-fluid levels at different heights within the same loop (upright)
  • Paucity of colonic gas
  • "String of pearls" sign - small trapped air bubbles in a row within fluid-filled obstructed loops
  • No pneumoperitoneum on upright view

CT Abdomen/Pelvis with IV Contrast:

  • Transition Point: Identified in the right lower quadrant, where dilated proximal small bowel (up to 4.5 cm) meets decompressed distal bowel
  • Cause: Band adhesion visible at the transition point causing sharp angulation of the bowel
  • Small Bowel Feces Sign: Present in the dilated ileum, indicating chronic/subacute obstruction
  • Bowel Wall: Normal wall thickness and enhancement throughout; no evidence of ischemia
  • Mesentery: No stranding or haziness to suggest strangulation
  • No closed loop: Single transition point without evidence of two-point obstruction
  • Free Fluid: Minimal physiologic fluid in the pelvis

Key Interpretation: The findings are consistent with complete small bowel obstruction due to adhesive band from prior surgery. The absence of bowel wall thickening, abnormal enhancement, mesenteric haziness, or pneumatosis indicates no current signs of strangulation or ischemia.

Diagnosis

Complete small bowel obstruction secondary to adhesive band; no evidence of strangulation

Management

  1. NPO status with nasogastric tube decompression
  2. IV fluid resuscitation with correction of electrolyte abnormalities
  3. Foley catheter for strict monitoring of urine output
  4. Serial abdominal examinations every 4-6 hours
  5. Trial of non-operative management for 24-48 hours given no signs of strangulation
  6. Repeat CT if clinical deterioration or failure to improve
  7. Surgical consultation with plan for operative intervention if:
  • Peritoneal signs develop
  • Fever or leukocytosis suggesting ischemia
  • Failure to resolve with conservative management by 48-72 hours

Radiological Image

Image Description: CT scan demonstrating small bowel obstruction with dilated proximal loops and a clear transition point where the bowel caliber changes from dilated to decompressed. The small bowel feces sign is visible in the dilated loops.

Source: Wikimedia Commons - "CT scan showing small bowel obstruction" URL: https://commons.wikimedia.org/wiki/File:Upright_abdominal_X-ray_demonstrating_a_small_bowel_obstruction.jpg License: Creative Commons Attribution-Share Alike 3.0 Unported

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