What is the most likely site of volvulus in a patient with severe abdominal pain, absolute constipation, and a palpable mass in the left lumbar and hypochondrium?

Sigmoid Colon Volvulus

The most likely site of volvulus in this patient is the sigmoid colon (Answer C). This 55-year-old man with chronic constipation requiring laxatives, presenting with severe abdominal pain, absolute constipation, and a palpable mass in the left lumbar and hypochondrium, demonstrates the classic presentation of sigmoid volvulus.

Clinical Reasoning

The key diagnostic features pointing to sigmoid volvulus include:

• Chronic constipation with frequent laxative use is one of the most common predisposing factors for sigmoid volvulus, along with anatomic predisposition (dolicho-sigmoid) 1

• The location of the palpable mass in the left lumbar and hypochondrium is pathognomonic for sigmoid volvulus, as the distended sigmoid colon typically presents in this anatomic location 2

• The classic triad of symptoms (abdominal pain, constipation, and abdominal distension) is present in 88% of endemic sigmoid volvulus cases and 33% of sporadic cases 2

• Age and gender demographics align perfectly—sigmoid volvulus preferentially affects elderly males (age >70 in Western countries), with mean age between 56-77 years 1

Why Not Other Sites?

Cecal volvulus is less likely because:

• It typically affects younger females (age ≤60) rather than middle-aged to elderly males 1
• Cecal volvulus would present with a mass in the right lower quadrant or right hypochondrium, not the left 3
• The patient's chronic constipation and laxative use pattern is more characteristic of sigmoid volvulus 1

Transverse colon and rectal volvulus are extremely rare:

• Transverse colon volvulus requires unusual anatomic circumstances of a long mesentery and mobile colon 4, 5
• Rectal volvulus is not a recognized clinical entity in standard classifications 6

Pathophysiology Context

Understanding the mechanism helps confirm the diagnosis:

• Dolicho-sigmoid (elongated sigmoid colon on a narrow mesenteric base) is the most commonly cited predisposing factor 1
• The combination of a high and wide meso-sigmoid with a narrow root predisposes to sigmoid volvulus 1
• Chronic constipation and frequent laxative use contribute to the development of this anatomic predisposition 1

Critical Next Steps

Immediate diagnostic workup should include:

• Plain abdominal radiographs as first-line imaging, looking for the classic "coffee bean sign" 1, 2
• Abdominal CT as the gold standard, which reveals dilated colon with air/fluid level and the "whirl sign" representing twisted colon and mesentery 1, 2
• Assessment for peritoneal signs, though their absence does not rule out bowel ischemia 2

Management depends on presentation:

• If septic shock, bowel ischemia, or perforation is present, urgent upfront surgery is mandatory 1
• Without definitive surgical management, recurrence rates are extremely high (45-71%) 2