SMLEREVISE

Volvulus

Medically Reviewed by Dr. M. Salar Raza | Official SCFHS 2026 Blueprint

Clinical Pathway

Volvulus is a medical condition characterized by the twisting of a loop of intestine around itself and its mesentery, leading to bowel obstruction and potential compromise of blood supply (ischemia). It is a surgical emergency that can affect any part of the gastrointestinal tract, most commonly the sigmoid colon or cecum in adults, and the midgut in infants. Urgent surgical intervention is the definitive treatment for most cases of volvulus to untwist the bowel (detorsion) and assess for viability. If the bowel is found to be gangrenous or non-viable, resection of the affected segment with either primary anastomosis or ostomy formation (e.g., colostomy) is performed. In select cases of sigmoid volvulus, endoscopic detorsion may be attempted as a bridge to elective surgery or in stable, non-ischemic patients. Patients typically experience sudden onset of severe, colicky abdominal pain that may be constant, accompanied by abdominal distension and obstipation (inability to pass flatus or stool). Nausea and vomiting are common, and in infants, bilious vomiting is a key sign of midgut volvulus. As ischemia progresses, signs of peritonitis, such as guarding, rigidity, and rebound tenderness, may develop.

Clinical Reasoning

The primary mechanism involves the rotation of a segment of bowel on its mesenteric axis, causing simultaneous occlusion of the intestinal lumen and the mesenteric blood vessels. This results in progressive bowel obstruction proximally and venous congestion, followed by arterial insufficiency in the twisted segment. If left untreated, this can rapidly progress to bowel ischemia, necrosis, perforation, and peritonitis. The prognosis for volvulus depends critically on the timeliness of diagnosis and intervention. Early surgical correction before the onset of bowel ischemia or perforation significantly improves outcomes and reduces morbidity. Delayed treatment, particularly once bowel gangrene and perforation have occurred, carries a high risk of complications, including sepsis, multi-organ failure, and death. Congenital intestinal malrotation (especially for midgut volvulus in infants),Redundant or elongated mesentery (common in sigmoid volvulus in elderly individuals),Chronic constipation or a high-fiber diet (contributing to colonic distension),Hirschsprung's disease or other conditions causing abnormal bowel motility,Prior abdominal surgery or adhesions (can create a fixed point for twisting),Pregnancy (due to uterine displacement of bowel)

Sample MCQ

A 68-year-old patient presents to the emergency department with severe lower abdominal pain associated with progressive distension. On examination, the abdomen is hugely distended and tympanic. Digital rectal examination reveals an empty rectum. An abdominal X-ray demonstrates a massively dilated, inverted U-shaped loop of bowel with a converging 'Y' configuration at its base, consistent with a sigmoid volvulus. Which of the following is the most appropriate intervention?

  • AFlexible sigmoidoscopy for detorsion and decompression
  • BImmediate exploratory laparotomy and sigmoid resection
  • CComputed tomography (CT) scan of the abdomen and pelvis with intravenous contrast
  • DWater-soluble contrast enema for diagnostic confirmation and reduction

Correct Answer: A

### TLDR Sigmoid volvulus in a stable patient with no signs of perforation or ischemia is primarily managed by endoscopic detorsion. Flexible sigmoidoscopy is the initial intervention of choice, offering both diagnosis and immediate therapeutic decompression. ### Comparison Table | Option | Mechanism | Clinical Nuance | Key Distinction | |---|---|---|---| | **Flexible sigmoidoscopy for detorsion and decompression** | Endoscopic untwisting, gas/stool suction. | First-line, therapeutic, avoids immediate surgery. | Both diagnostic and therapeutic in stable patients. | | Immediate exploratory laparotomy and sigmoid resection | Surgical removal of twisted, necrotic bowel. | For unstable patients or failed endoscopy. | Invasive, definitive, reserved for complications/failure. | | Computed tomography (CT) scan of the abdomen and pelvis with intravenous contrast | Advanced imaging for diagnosis/complications. | Confirms diagnosis, rules out ischemia/perforation. | Diagnostic, not therapeutic; often done after X-ray. | | Water-soluble contrast enema for diagnostic confirmation and reduction | Contrast outlines twisted colon, may untwist. | Diagnostic; less effective for reduction than endoscopy. | Diagnostic, sometimes therapeutic; risk of perforation. | ### Detailed Breakdown The patient presents with classical symptoms and radiological findings of a sigmoid volvulus: severe lower abdominal pain, progressive distension, tympanic abdomen, empty rectum on DRE, and an inverted U-shaped loop of bowel with a 'Y' configuration on X-ray. Importantly, the scenario does not describe signs of peritonitis, sepsis, or bowel ischemia (e.g., fever, tachycardia, localized tenderness, guarding, rebound, metabolic acidosis), which would indicate a complicated volvulus. Therefore, the patient is presumed stable. **Flexible sigmoidoscopy for detorsion and decompression** is the most appropriate initial intervention in a stable patient with sigmoid volvulus. This endoscopic procedure serves two critical purposes: it confirms the diagnosis visually (though the X-ray is already highly suggestive) and, more importantly, provides immediate therapeutic decompression by untwisting the bowel and aspirating gas and fecal material. This can relieve the obstruction, reduce the risk of ischemia, and often obviate the need for emergent surgery. Success rates for endoscopic detorsion are high, and it is a less invasive approach than surgery. Immediate exploratory laparotomy and sigmoid resection would be indicated if there were signs of bowel ischemia, perforation, peritonitis, or if endoscopic detorsion failed. While definitive, it is a major surgical procedure with associated risks and is not the first-line management for an uncomplicated sigmoid volvulus. A Computed tomography (CT) scan of the abdomen and pelvis with intravenous contrast can confirm the diagnosis of volvulus and assess for complications like ischemia or perforation. However, the X-ray findings are already highly characteristic, and the immediate priority for a stable patient is therapeutic decompression rather than further diagnostic imaging. Delaying decompression to obtain a CT scan could prolong ischemia if present. A water-soluble contrast enema can be diagnostic, showing the classic "bird's beak" appearance at the site of the twist. While it can sometimes induce detorsion, its therapeutic efficacy is generally lower than that of flexible sigmoidoscopy. Furthermore, there is a theoretical risk of perforation if the bowel is already ischemic or compromised, making it a less preferred primary therapeutic option compared to endoscopy in this context.

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