Sigmoid volvulus and incidental enterobiasis in a young adult: a case report.

BACKGROUND: Sigmoid volvulus is a disease that typically occurs in elderly patients with chronic constipation and an elongated sigmoid mesentery. Its occurrence in previously healthy young adults is uncommon, often with delayed diagnosis, and may coexist with under-recognized predisposing factors. In this case, family clustering of vague gastrointestinal symptoms and a coexisting parasitic infestation are most likely incidental rather than causative.

CASE PRESENTATION: A previously healthy young Saudi woman presented with 2 weeks of intermittent colicky abdominal pain, low-volume diarrhea, and a final acute episode of severe pain with progressive abdominal distension. Her 15-year-old sister had recently been diagnosed with enterobiasis with a similar symptom pattern. Vital signs were stable; abdominal examination showed mild distension without peritonism. Plain radiography demonstrated dilated colonic loops, and contrast-enhanced computed tomography revealed a markedly dilated sigmoid colon (up to 85 mm), an abrupt collapse point, and the whirl sign, consistent with sigmoid volvulus. Endoscopic detorsion was achieved successfully with placement of a rectal decompression tube; during colonoscopy, a single adult gravid Enterobius vermicularis was retrieved and confirmed parasitologically (characteristic ova demonstrated within the gravid female), prompting consultation with an infectious diseases team and a course of mebendazole. Following clinical stabilization, the patient underwent laparoscopic sigmoidectomy with extracorporeal stapled colorectal anastomosis. Operative findings confirmed a redundant sigmoid colon without ischemia, perforation, or contamination. Histopathology revealed ischemic-type changes (mucosal atrophy, submucosal edema, congested vessels, and hypertrophied muscularis propria) with viable resection margins. At the 4-week follow-up, she was asymptomatic and repeat parasitological testing (stool microscopy and adhesive tape examination) showed no E. vermicularis ova.

CONCLUSION: Sigmoid volvulus should be considered in young adults presenting with acute colonic obstruction, particularly when imaging features are characteristic. A two-stage strategy of colonoscopic detorsion followed by definitive laparoscopic sigmoidectomy is feasible and effective in hemodynamically stable patients without ischemia. The clinical relevance of the coexisting enterobiasis remains hypothesis-generating and should not be overstated.