Gastrointestinal · PANCE / PANRE

Volvulus (Sigmoid and Cecal)

Twisting of bowel on its mesentery → closed-loop obstruction with risk of ischemia; sigmoid most common in elderly, cecal in younger adults.

Also known as: sigmoid volvulus, cecal volvulus, colonic volvulus

Overview

Rotation of a segment of bowel along its mesenteric axis, producing a closed-loop obstruction with progressive risk of ischemia, necrosis, and perforation. In adults the colon is most commonly affected (sigmoid > cecal); midgut volvulus in neonates is associated with malrotation.

Epidemiology

Sigmoid volvulus accounts for ~60-75% of colonic volvulus and occurs in older, institutionalized, debilitated patients with chronic constipation; common in Africa, the Middle East, and South America. Cecal volvulus accounts for ~25-40% and affects younger adults (30-60 yr), women > men. Overall, volvulus causes 5-10% of large bowel obstruction in the US.

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Risk factors

  • Sigmoid: chronic constipation, redundant sigmoid (long mesentery), neuropsychiatric disease (Parkinson, schizophrenia), high-fiber diet, institutionalization, prior abdominal surgery
  • Cecal: long mobile cecum (congenital fixation failure), pregnancy, prior abdominal surgery, recent colonoscopy
  • Both: laxative abuse, dysmotility, hospitalization with prolonged ileus

Pathophysiology

A redundant mobile loop with a narrow mesenteric base rotates around its axis, producing a closed-loop obstruction at the twist. Venous outflow is impaired first, leading to edema, then arterial inflow is compromised, producing ischemia, gangrene, and perforation. Cecal 'bascule' is a variant in which the cecum folds anteriorly without true rotation.

Clinical presentation

Symptoms

  • Sigmoid: gradual onset cramping abdominal pain, abdominal distention, obstipation, vomiting (late)
  • Cecal: more acute presentation with RLQ or periumbilical pain, distention, vomiting (earlier and more bilious than sigmoid)
  • Tympanic distention out of proportion to systemic symptoms early on
  • Late: signs of ischemia — severe pain, fever, peritonitis

Signs / physical exam

  • Massively distended, tympanitic abdomen
  • Bowel sounds high-pitched then absent
  • Tenderness, peritoneal signs suggest ischemia or perforation
  • Empty rectum on DRE

Classic findings

Sigmoid: 'coffee bean' or 'bent inner tube' sign on abdominal radiograph, with the apex pointing toward the RUQ. Cecal: dilated cecum displaced to the LUQ ('embryonic position'), with a 'kidney bean' or 'comma' shape.

Differential diagnosis

  • Colorectal malignancy with obstruction — Older adult with weight loss, progressive constipation, anemia; mass on CT or colonoscopy
  • Pseudo-obstruction (Ogilvie syndrome) — Massive cecal dilation without mechanical obstruction; postoperative or critically ill patients; rectal tube and neostigmine
  • Diverticulitis with stricture — LLQ pain, fever, history of diverticulosis; CT shows pericolic inflammation
  • Inflammatory bowel disease with stricture — Younger patient with chronic diarrhea, bloody stools
  • Adhesive small bowel obstruction — Prior abdominal surgery, dilated small bowel loops with transition point
  • Fecal impaction — Hard stool in rectum on DRE; relieved by disimpaction

Diagnostic workup

Diagnostic criteria

Imaging demonstration of closed-loop colonic obstruction with mesenteric twist and characteristic radiographic appearance.

Labs

  • CBC, BMP, lactate (elevated in ischemia), coagulation studies, type and crossmatch

Imaging

  • Abdominal radiograph — often diagnostic for sigmoid (coffee bean sign) or cecal (LUQ kidney bean)
  • CT abdomen/pelvis with IV contrast — confirms diagnosis ('whirl sign' of twisted mesentery), identifies ischemia (pneumatosis, portal venous gas, bowel wall thickening), and excludes alternatives
  • Water-soluble contrast enema — 'bird's beak' tapering at the point of torsion (sigmoid)

Complications

  • Bowel ischemia and necrosis
  • Perforation and feculent peritonitis
  • Septic shock, multiorgan failure
  • Recurrence (sigmoid: high without surgery; cecal: lower if resected)
  • Anastomotic leak, surgical site infection, stoma complications

PANCE pearls

  • Sigmoid volvulus in a chronically constipated nursing home patient — picture the coffee bean pointing to the RUQ.
  • Cecal volvulus in a younger pregnant patient or after recent colonoscopy — picture the dilated cecum displaced to the LUQ.
  • Endoscopic detorsion is appropriate ONLY for sigmoid volvulus without ischemia — NEVER for cecal volvulus as primary therapy.
  • Recurrence after detorsion alone is high — definitive sigmoidectomy should be done during the same admission.
  • Cecal bascule is an anterior folding of the cecum without true rotation; same clinical presentation and management.

References

  • ASCRS 2016 — American Society of Colon and Rectal Surgeons clinical practice guidelines for the management of colonic volvulus (Vogel et al., Dis Colon Rectum 2016)
  • WSES 2018 — World Society of Emergency Surgery (WSES) guidelines on colon and rectal obstruction

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