Glutaraldehyde colitis following endoscopy: clinical and pathological features and investigation of an outbreak.

Although potentially noxious compounds are used routinely to disinfect endoscopes, reports of their inadvertent introduction to the gastrointestinal tract, usually attributed to the retention of disinfectant within endoscope channels, are rare. This case report describes the clinical features of glutaraldehyde-induced colitis and the pathology of the mucosal injury in four patients, in at least one of whom the disinfectant was not retained in the endoscope itself. Within 3 months, three patients experienced severe acute proctocolitis < 6 hours after a sigmoidoscopy showing no abnormalities, performed in a small endoscopy unit. Investigation of the unit's protocols suggested that the most likely cause was retention of 2% glutaraldehyde disinfectant in the endoscope channels, and changes were made to prevent this. When a fourth case occurred 5 months later, the source of the glutaraldehyde was found to be the tubing connecting water bottles to the endoscopes, which was disinfected rigorously but flushed inconsistently between cases. Glutaraldehyde-induced colitis seems similar to ischemic colitis in biopsy specimens and cannot be diagnosed by histological analysis alone. Acute colitis occurring within 24 hours of a colonoscopy showing no abnormalities should be considered iatrogenic and should lead to an investigation of procedures in use for cleaning and disinfecting endoscopic equipment.