Acute Colonic Pseudo-Obstruction

Abstract

Purpose: Acute colonic pseudo-obstruction is characterized by symptoms, signs and radiological appearance of acute large bowel obstruction in the absence of a true mechanical obstruction. The pathophysiology is not well understood. A proposed theory involves transient impairment of the sacral parasympathetic nerves causing atony of the distal large bowel resulting in functional obstruction. Methods: We present a case of a patient with Guillain-Barré syndrome complicated by acute colonic pseudo-obstruction, in whom neostigmine could not be used. Results: A 57 year old man with Guillain-Barré syndrome and progressive ascending muscular weakness was hospitalized for significant autonomic dysfunction and pronounced muscular weakness. He developed diffuse abdominal pain and distension, and was unable to pass gas or feces on hospital day 5. The physical exam was significant for abdominal distension, hyperactive bowel sounds, and diffuse abdominal tenderness. An abdominal CT showed dilated colon and cecum with a maximum diameter of 8.3 cm without associated abnormality of the bowel wall or proximal bowel dilation, consistent with acute colonic pseudo-obstruction. Successful endoscopic colonic decompression was performed the next day and supportive measures continued, including nasogastric (NG) suction and maintaining electrolyte balance. The patient developed recurrent distension within 24 hours. Neostigmine was contraindicated because of autonomic dysfunction and he failed to respond to erythromycin. Tegaserod 6 mg was given every 12 hours per NG tube and within 14 hours the patient started passing gas and had a spontaneous bowel movement. Abdominal pain and distension resolved, confirmed by an abdominal film. The patient continued to receive tegaserod until discharge 7 days later with no recurrence of obstructive symptoms. Conclusion: Treatment options for acute colonic pseudo-obstruction have had variable outcomes and include medications (neostigmine and erythromycin), endoscopic decompression, percutaneous tube cecostomy and colectomy. To our knowledge, this is the first case report of acute colonic pseudo-obstruction with a clinical response to treatment with tegaserod, a partial 5-HT4 receptor agonist. 5-HT4 receptor agonists may be a viable option in the treatment of acute colonic pseudo-obstruction.