Sigmoid Volvulus

Sigmoid Volvulus

Definition:

• • A twist of the sigmoid colon around its mesentery, leading to bowel obstruction and potential ischaemia.

Aetiology and Risk Factors:

• • Chronic constipation.
  • Redundant or elongated colon.
  • Previous abdominal surgery.
  • Neurological or psychiatric conditions.
  • Elderly population.
  • High-fibre diet (observed in some populations).

Clinical Features:

• • Abrupt onset of severe abdominal pain.
  • Distension, particularly in the lower abdomen.
  • Constipation and absence of flatus.
  • Vomiting (may become faeculent if not promptly treated).
  • Examination may reveal a tympanitic, tender abdomen.

Investigations:

• • Plain abdominal X-ray:
    • “Coffee bean” or “omega loop” sign.
    • Distended sigmoid loop pointing to the right upper quadrant.
  • CT Scan:
    • Confirms diagnosis and assesses for bowel ischaemia.
  • Blood tests:
    • May show raised white cells, lactate (if ischaemia present).

X-ray showing sigmoid volvulus

Management:

• • Initial:
    • Resuscitation with IV fluids.
    • Nasogastric tube insertion to decompress the stomach / GI tract.
    • Antibiotics if signs of systemic infection or ischaemia.
  • Definitive:
    • Endoscopic decompression (sigmoidoscopy):
      • First-line for most patients.
      • May be followed by elective sigmoid colectomy to prevent recurrence.
    • Surgery:
      • Required if there’s suspicion of bowel ischaemia, perforation, or failed non-surgical decompression.
      • Sigmoid colectomy is the procedure of choice.

Complications:

• • Bowel ischaemia or gangrene.
  • Perforation leading to peritonitis.
  • Recurrence if definitive surgical management is not undertaken.

Prognosis:

• • Prompt diagnosis and treatment lead to favourable outcomes.
  • Risk of morbidity and mortality increases with delayed intervention, especially if bowel ischaemia occurs.

Image reference: Radiopaedia.org. From the case: 5575