Common Presentation of a Common Disease in an Unusual Age

Abstract

A n 8-year-old boy with chronic functional constipation presented to the emergency department after 5 days of periumbilical abdominal pain, nonbilious vomiting, and failure to pass stool. The patient was in distress and on examination had abdominal distension, generalized tenderness, hyperactive bowel sounds, and normal vital signs. Abdominal radiograph (AXR) demonstrated a dilated and displaced sigmoid (Figure 1, A and B) with a paucity of gas in the rectum and normal small bowl supportive of colonic obstruction. Moreover, there was a dense, obliquely oriented line in the left upper quadrant due to apposition of bowel wall from multiple displaced sigmoid bowel loops, an appearance described as the "coffee bean" sign. Findings were confirmed on computed tomography (CT), which further illustrated a nondilated cecum (Figure 2, A and B; available at www .jpeds.com). The clinical presentation and classic imaging findings led to a diagnosis of sigmoid volvulus. After nasogastric tube decompression, a pediatric colonoscope was introduced to the sigmoid colon where, at 20 cm from the anal verge, "a valvelike"tapering of the colon was seen. The scope was pushed gently through this "valve" to reveal a dilated proximal colon with normal mucosa. The colonoscope was passed into the descending colon and exchanged for a 24-F red rubber catheter. Within 24 hours, the patient had a normal abdominal examination and passed flatus and stool. After advancement to a normal diet, the rectal tube was removed and the patient was discharged. He was discharged on 17 g of polyethylene glycol twice a day. Two-week and 6-month outpatient follow-up was unremarkable. Although sigmoid volvulus is well reported among adults, it is uncommon among children and occurs when the sigmoid colon wraps around the mesentery, leading to an obstruction. 1,2 The main risk factor for sigmoid volvulus among children is colonic dysmotility, as seen with chronic constipation. Imaging findings on both AXR and CT are similar and specific for sigmoid volvulus, although a diagnosis can be made with AXR alone, with CT reserved for cases of equivocal findings. On both modalities, a distended and displaced sigmoid colon with transition to a decompressed rectum is diagnostic for sigmoid volvulus. 3 These findings must be differentiated from cecal volvulus, where the transition point is noted within a displaced cecum. Unlike cecal volvulus, which requires surgical intervention, most cases of sigmoid volvulus can be treated with endoscopic decompression and the placement of a rectal tube. Early diagnosis of the sigmoid volvulus is critical because delay can lead to ischemia, perforation, peritonitis, and death. ■