Diagnosis: Sigmoid Volvulus

The patient's KUB revealed a large loop of dilated colon measuring up to 13.4 cm in diameter pointing towards the left upper quadrant. Gas is also seen throughout the entire colon.

A CT scan of his abdomen and pelvis similarly showed diffuse dilatation of large bowel loops up to 11 cm with bowel dilatation extending down to the upper pelvis where there is an abrupt narrowing of sigmoid colon and a whirl sign, consistent with sigmoid volvulus. 

Colorectal surgery was urgently consulted and the patient underwent sigmoidoscopy with failure of the scope to pass the obstruction or decompress the bowel. The gastrointestinal service was then consulted and the patient underwent a colonoscopy in which the patient's cecum was reached by the endoscope however the procedure also failed to decompress the bowel.

The patient was then taken to the OR by colorectal surgery for laparoscopic resection of the sigmoid colon and imobilization of the splenic flexure. The patient did well post-operatively and was discharged from the hospital 2 days later. 

Volvulus: when a loop of bowel twists and obstructs the intestinal lumen; if severe enough may compromise vascular supply to the colon

Epidemiology

• more common in older adults with mean age 60 to 70 years, however all age groups are affected
• most common portions of bowel involved  are the sigmoid colon and cecum  occurring at roughly equal frequency

Presentation

• Hallmark of sigmoid volvulus is a triad of abdominal pain, distention, and constipation
• Distended tympanic abdomen on exam
• Onset may be acute or insidious with many days before discovery
• Severe pain, absent bowel sounds, and cardiovascular instability should prompt concern for gangrenous bowel 

Workup

• Diagnosis is made by plain radiographs in most cases 
• CT and sigmoidoscopy both are highly accurate at making the diagnosis

Management

• If clinical evidence of gangrenous bowel is absent (minimal pain, stable vital signs) then endoscopic detorsion by an experienced operator can be attempted
• successful in 50-90% cases  
• If gangrenous bowel identified on endoscopy, or endoscopic decompression unsuccessful --> surgical management is indicated

Disposition and Outcome

• All patients with volvulus require hospitalization for intervention
• Rate of recurrence estimated to be as high as 60%! - Therefore elective surgical resection of redundant sigmoid colon is recommended
• Mortality rate:
• Overall - 20%
• Patients with gangrene - 50% 

References: 

Rosen's Emergency Medicine Concepts and Clinical Practice, 8th Ed, 2014, Chapter 95: Disorders of the Large Intestine by Michael A. Peterson