Large-bowel obstruction during oral bowel preparation for stenosing low rectal adenocarcinoma: A case report and review of literature

BACKGROUND Establishing a histopathologic diagnosis of a low rectal lesion generally requires endoscopic tissue sampling.When the lesion causes luminal stenosis, incomplete largebowel obstruction may be present despite continued passage of flatus or stool.Obstructive symptoms may develop or worsen during oral bowel preparation.CASE SUMMARY A 56-year-old woman presented with increased stool frequency for 10 days and one episode of hematochezia.Digital rectal examination revealed a mass 5-6 cm from the anal verge.Before preparation, she continued to pass flatus and stool and had mild distension.After ingesting approximately 1 L of polyethylene glycol electrolyte solution, she developed abdominal pain and worsening distension.Radiographs showed air-fluid levels and dilated bowel loops.An enema provided transient relief, but neither transanal drainage nor nasogastric decompression produced sustained improvement.A diverting transverse loop colostomy relieved the obstructive symptoms.Limited distal bowel preparation with an enema enabled endoscopic biopsy, which confirmed poorly differentiated rectal adenocarcinoma.Treatment with capecitabine plus oxaliplatin began on postoperative day 17.She completed three cycles and subsequently developed recurrent acute kidney injury with bilateral hydronephrosis.During intensive care after bilateral ureteral stenting, renal function initially improved, but hematuria persisted.CONCLUSION Continued stool or flatus passage does not exclude incomplete obstruction in rectal stenosis.Assess obstruction risk before oral bowel preparation.4 / 36