An Unusual Case of Post Colonoscopy Colitis - A Pathological Surprise

Abstract

Acute colitis can be caused by infection, inflammation or ischemia. Ischemic colitis is the most common cause of intestinal ischemia. Colitis induced by colonoscopy is a very rare complication and has been mostly described in patients with an underlying vascular disease, connective tissue disorder or other risk factors for ischemia. There has been a historic association with the disinfectant glutaraldehyde, which is not used anymore as a cleaning agent. We present a 53 year old gentleman with a 3 week history of recurrent, non-radiating, periumbilical dull aching abdominal pain associated with persistent non-bloody diarrhea of about 6-7 bowel movements per day. His symptoms started about 2 days after a screening colonoscopy, which revealed 3 polyps largest of 2 cm, with no signs of colitis. He is known to have diabetes, hypertension, chronic kidney disease and was afebrile on presentation with no tachycardia or hypotension. Physical examination revealed diffuse abdominal tenderness with no rebound, guarding or rigidity. Labs were evident of hypokalemia, elevated BUN and Creatinine but with no leukocytosis. Stool cultures were negative for bacterial infection. Stool ova, parasites and Clostridium difficile toxin were also negative. CT abdomen revealed diffuse wall thickening of the large bowel, suggestive of colitis. Repeat colonoscopy showed mild diffuse erythema throughout with areas of erosion in the rectum that were biopsied. Viral cultures, AFB culture and CMV IgM were negative. He was discharged empirically on levofloxacin and metronidazole with improvement of his diarrhea on subsequent clinic visits. To our surprise, the pathology revealed non-specific chronic inflammation with areas of ischemic changes suggestive of ischemic colitis. Our case is unique unlike other reported cases in literature due to various reasons. Our patient developed colitis in the absence of a pre-existing bowel disease, and against the historically well described glutaraldehyde induced colitis as we don't use glutaraldehyde in our endoscopy suites. In a case series review, it was found that colonoscopy induced colitis may be associated with bowel spasms secondary to stress, hypovolemia from inadequate bowel preparation, excessive colonic insufflation and prolonged examination during colonoscopy. Hence, it is important for gastroenterologists to think about these factors while performing colonoscopies, to possibly decrease the chance of inducing colitis post colonoscopy.1485_A Figure 1. Coronal Section of CT Abdomen showing diffuse Colitis1485_B Figure 2. Colonoscopy showing mild colitis with erosion and erythema1485_C Figure 3. Biopsy of Colon showing amorphous, eosinophilic, stroma with minimal inflammatory cells suggestive of ischemia