AKT · Gastroenterology/Acute abdomen & surgical

Volvulus

Torsion of a bowel loop around its mesentery → closed-loop obstruction (sigmoid; caecal; neonatal midgut)

Overview

Twisting of a bowel loop around its mesenteric axis, causing a closed-loop obstruction with ischaemia/perforation risk. SIGMOID volvulus — elderly, constipated, institutionalised; AXR shows a large 'coffee-bean'/inverted-U loop arising from the pelvis. CAECAL volvulus — younger, embryo-shaped loop in the upper abdomen. Neonatal MIDGUT volvulus (with malrotation) — bilious vomiting in a neonate, a surgical emergency (cross-ref child health).

Recognise

Abdominal distension, colicky pain, absolute constipation, vomiting (closed-loop large-bowel obstruction)
SIGMOID (commonest): elderly, chronic constipation, neuropsychiatric/institutional; AXR 'COFFEE-BEAN' loop pointing to the pelvis
CAECAL: younger adults; embryo/comma-shaped loop in the LUQ; NEONATAL midgut volvulus: bilious vomiting (malrotation) — emergency

Red flags

Ischaemia/perforation (peritonism, raised lactate, free gas) → emergency surgery
Neonatal bilious vomiting = malrotation/midgut volvulus until proven otherwise (urgent upper GI contrast/surgery)

Differentials & how to tell them apart

Other large-bowel obstruction (cancer/diverticular stricture)transition point/mass on CT rather than a twisted loop

Pseudo-obstruction (Ogilvie)colonic dilatation without a mechanical twist

Toxic megacoloncolitis + systemic toxicity, non-obstructive

Sigmoid volvulus — dilated 'coffee-bean' loop arising from the pelvis (AXR)
Mont4nha / CC0 — Wikimedia Commons

Investigations

AXR ('coffee-bean' sigmoid; embryo-shaped caecal); CT confirms (whirl sign, transition point, viability). Neonate: urgent upper GI contrast study. Lactate/FBC.

Management

Sigmoid → endoscopic decompression (flatus tube); caecal/complicated → surgery

1Resuscitate. SIGMOID volvulus without ischaemia: endoscopic decompression (flexible sigmoidoscopy + flatus tube) — often successful, though it recurs.Gate: CAECAL volvulus, a failed/recurrent sigmoid decompression, or any sign of ISCHAEMIA/perforation → surgery (resection); neonatal bilious vomiting is midgut volvulus until excluded — urgent contrast/surgery
2Recurrent sigmoid volvulus → elective sigmoid colectomy; caecal volvulus → right hemicolectomy; resect non-viable bowel.

Sigmoid: endoscopic decompression (flexible sigmoidoscopy + flatus tube) — first-line if no ischaemia/perforation — detorts and decompresses

Surgery — caecal volvulus, failed/recurrent sigmoid decompression, or ischaemia/perforation (resection)

Key points

Distension + closed-loop obstruction + 'coffee-bean' loop from the pelvis = sigmoid volvulus (elderly/constipated) → endoscopic decompression. Caecal volvulus (younger, LUQ embryo loop) → surgery. Neonatal bilious vomiting = midgut volvulus — emergency.

Monitor & prognosis

Recurrence; viability.

Good if decompressed early; recurrence common for sigmoid.

Source: ACPGBI; RCS