A 72-year-old woman presents to the hospital with acute onset of severe abdominal pain, vomiting, and abdominal distension. She has no history of previous abdominal surgery. On examination, her abdomen is markedly distended and tympanitic. Plain abdominal radiograph shows a massively dilated loop of bowel in the left lower quadrant with a characteristic 'coffee-bean' or 'omega' sign. The rest of the colon is collapsed. CT abdomen confirms twisting of the sigmoid colon at the pelvic brim. What is the most appropriate next step in management?

Explanation

## Sigmoid Volvulus: Diagnosis and Management **Key Point:** Endoscopic decompression is the first-line treatment for uncomplicated sigmoid volvulus in a hemodynamically stable patient without signs of perforation or gangrene. ### Imaging Diagnosis of Sigmoid Volvulus **High-Yield:** The 'coffee-bean' or 'omega' sign on plain film is pathognomonic for sigmoid volvulus. It represents the twisted sigmoid colon at the pelvic brim. CT shows the transition point where the twisted mesentery creates a focal narrowing. | Feature | Significance | |---------|-------------| | **Coffee-bean sign** | Twisted sigmoid loop, pathognomonic | | **Collapsed distal colon** | Obstruction at the twist site | | **Absence of small bowel dilatation** | Confirms large bowel obstruction | | **Mesenteric twist on CT** | Confirms diagnosis and rules out other causes | ### Management Algorithm ```mermaid flowchart TD A[Sigmoid Volvulus Confirmed]:::outcome --> B{Signs of Perforation or Gangrene?}:::decision B -->|Yes: Fever, Peritonitis, Lactate > 2| C[Immediate Laparotomy + Sigmoid Resection]:::urgent B -->|No: Hemodynamically Stable| D[Attempt Endoscopic Decompression]:::action D --> E{Successful Reduction?}:::decision E -->|Yes| F[Rectal Tube + IV Fluids + Bowel Prep]:::action E -->|No| G[Laparotomy + Sigmoid Resection]:::action F --> H[Elective Sigmoidoscopy/Colostomy in 48-72 hrs]:::action H --> I[Definitive Surgery: Sigmoid Resection]:::action ``` **Clinical Pearl:** Endoscopic decompression succeeds in 60–90% of uncomplicated cases. A rectal tube is left in place for 24–48 hours to prevent immediate recurrence. Definitive treatment (elective sigmoid resection) is performed after bowel preparation to reduce recurrence risk (40–50% without surgery). ### Why Surgery Is Not First-Line Here **Tip:** Immediate surgery is reserved for: - Perforation (free air on imaging) - Signs of gangrene (fever, peritonitis, elevated lactate, acidosis) - Failed endoscopic decompression - Recurrent episodes In this case, the patient is hemodynamically stable with no mention of perforation or gangrene, making endoscopic decompression appropriate. **Mnemonic:** **VOLVULUS FIRST-LINE = ENDO** (Endoscopy first in uncomplicated cases; surgery for complicated/recurrent) [cite:Harrison 21e Ch 297; Robbins 10e Ch 17]