# Sigmoid Volvulus > Sigmoid volvulus for NEET-PG Surgery: coffee-bean sign, sigmoidoscopic detorsion, high recurrence, elective sigmoid colectomy, Indian pattern. - Canonical URL: https://prepelephant.com/topics/neet-pg/surgery/volvulus-sigmoid - Exam / course: NEET-PG · Subject: Surgery - Publisher: PrepElephant (https://prepelephant.com) — Prepared and reviewed by the PrepElephant Academic Review Team - First published: 2026-10-02 - Last updated: 2026-10-02 - How to cite: "Sigmoid Volvulus", PrepElephant, https://prepelephant.com/topics/neet-pg/surgery/volvulus-sigmoid ## Direct answer When an elongated, redundant sigmoid loop twists around its mesentery, the result is sigmoid volvulus — acute large bowel obstruction with massive abdominal distension, and in India among the commonest causes of acute intestinal obstruction in elderly men, linked to chronic high-residue vegetarian diets, constipation and institutionalisation. The abdominal film shows a hugely dilated loop arising from the pelvis — the coffee-bean or bent-inner-tube sign, apex pointing to the right upper quadrant — and CT adds the whirl sign of the twisted mesentery. Without peritonitis or bowel gangrene, the first maneuver is endoscopic detorsion with a rigid sigmoidoscope and insertion of a flatus tube for 48-72 hours, succeeding in 70-90 percent; because recurrence approaches half or more of patients (up to 90 percent lifelong), definitive sigmoid colectomy with primary anastomosis is recommended in the same admission in fit patients. Suspected gangrene or perforation means emergency laparotomy, usually a Hartmann procedure. ## What you must remember - **Predisposition anatomy:** a long sigmoid on a narrow-based, fatty mesentery twists around the axis of the sigmoid mesocolon; chronic constipation, high-fibre diet, old age, psychiatric illness and immobility (bedridden, post-stroke, institutionalised patients) are the classic hosts. - **Indian practice context:** sigmoid volvulus accounts for a striking share of adult large bowel obstruction in Indian series — particularly in southern India — in contrast to Western cohorts where cancer dominates; elderly men with lifelong vegetarian, high-roughage diets are the stereotype. - **Radiology:** plain film alone is diagnostic in 60-80 percent — the coffee-bean loop with its apex under the right diaphragm and haustra preserved; CT shows the whirl sign, the transition point and assesses viability. - **Endoscopic detorsion:** rigid sigmoidoscopy to the twist, gentle reduction, then a flatus tube left in situ 48-72 hours to keep the loop decompressed and prevent immediate retorsion; success 70-90 percent. Contraindicated when mucosa looks gangrenous or the abdomen has peritonitis. - **Recurrence is the rule:** after successful detorsion alone, roughly 40-60 percent recur (up to 90 percent long term), so a fit patient should have elective sigmoid colectomy with primary anastomosis during the same admission — mortality is far lower than emergency surgery. - **Gangrenous volvulus:** emergency resuscitation and laparotomy; resection with Hartmann's procedure when unprepped and contaminated. - **Caecal volvulus contrast:** presents younger, needs right hemicolectomy, and endoscopic detorsion generally has no role — a discriminating pair examiners repeatedly test. ## A typical exam case A 78-year-old man, a resident of an old-age home with chronic constipation, is brought in with three days of colicky pain, absolute constipation and an abdomen distended like a drum. He is dehydrated but afebrile with no peritonism. The plain film shows a single massively dilated loop rising from the pelvis towards the right upper quadrant. Resuscitation with fluids and electrolytes precedes everything. Rigid sigmoidoscopy reaches a spiral twist at about 15 centimetres; the mucosa beyond is pink and viable, the scope passes, the loop decompresses with a rush of gas and liquid stool, and a flatus tube is secured for two days. He improves. On day four, counselled about recurrence risk, he undergoes elective sigmoid colectomy with primary anastomosis and goes home cured. Had he arrived with tachycardia, peritonism and a feculent smell, the pathway shortens to emergency Hartmann's — resection, end colostomy, and closure of the rectal stump. ## Where students slip Two slips recur. First, detorsion is treated as the cure: candidates answer "sigmoidoscopic decompression" for definitive management, but the examiner wants the recurrence figure and the recommendation for same-admission colectomy in fit patients — that two-step answer earns the mark. Second, caecal and sigmoid volvulus are conflated: caecal volvulus appears on plain film as a comma-shaped loop pointing to the left upper quadrant, endoscopy is not useful, and right hemicolectomy is the operation. A third detail — the flatus tube left for 48-72 hours after detorsion — separates candidates who have actually read the procedure from those who know only its name. ## Frequently asked questions ### What is the classic radiological sign of sigmoid volvulus? A massively dilated loop arising from the pelvis — the coffee-bean or bent-inner-tube shape — with its apex under the right hemidiaphragm, on a plain film. ### How is uncomplicated sigmoid volvulus decompressed? Rigid sigmoidoscopy to the twist with gentle derotation, followed by a flatus tube left in situ for 48-72 hours; colonoscopic detorsion is an alternative in selected patients. ### Why is elective surgery advised after successful detorsion? Recurrence occurs in roughly 40-60 percent of patients after detorsion alone — up to 90 percent over a lifetime — so fit patients undergo sigmoid colectomy with primary anastomosis, usually in the same admission. ### What operation suits gangrenous sigmoid volvulus? Emergency laparotomy with resection of the gangrenous loop and a Hartmann procedure — end colostomy with rectal stump closure — in the unprepared, contaminated abdomen. ### How does caecal volvulus differ in management? Caecal volvulus occurs in younger patients, is diagnosed with a comma-shaped dilated caecum, does not respond to endoscopic detorsion reliably, and is treated by right hemicolectomy.