A 62 yo M presents to the ED with 1 week of abdominal distension with associated nausea and vomiting. He has had only 2 small bowel movements in the last week. He denies abdominal pain. On exam, his abdomen is distended and rigid. An obstruction series is obtained and shown below. What's the diagnosis? (scroll down for answer) 

Answer: Xray showing multiple air-fluid levels, concerning for obstruction

• CT A/P obtained (shown below)- diagnosis of Large bowel obstruction
• Most common cause of large bowel obstruction = neoplasm/mass
• Other causes: diverticulitis, sigmoid or cecal volvulus
• Other uncommon causes: adhesions, hernias, IBS, fecal impaction, intraluminal FB, intussusception
• LBO are less common than SBO
• Presenting sypmtoms: abdominal pain/distension, constipation
• CT A/P w/ IV contrast is imaging modality of choice
• Most require surgery
• Ogilvie Syndrome: acute colonic psuedo-obstruction due to loss of sympathetic innervation of colon (no actual mechanical obstruction)
• usually seen in severely ill patients with multiple comorbidities
• CT shows marked dilatation of the large bowel without any evidence of a marked transition point or obstructing lesion

References:

Jaffe T, Thompson WM. Large-Bowel Obstruction in the Adult: Classic radiographic and CT findings, etiology and mimics. Radiology. 2015 June;275(3):651-63.

Price TG, Orthober RJ. Bowel Obstruction. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 8eEds. Judith E. Tintinalli, et al. New York, NY: McGraw-Hill, 2016, pg 538-41