Glutaraldehyde as a possible cause of diarrhoea after sigmoidoscopy

An outbreak of proctitis at the start of a colorectal cancer screening programme utilizing flexible sigmoidoscopy prompted scrutiny of the incidence of this complication and the role of glutaraldehyde in its aetiology.

Questionnaires completed 1 day and 3 months after sigmoidoscopy were reviewed for 388 patients, and glutaraldehyde levels in the recycled rinse water of the endoscope washing machine were measured. The incidence of symptoms in the subsequent 612 patients after installation of a washer that does not recycle rinse water was examined.

Five patients (1.3 per cent) presented to hospital with bloody diarrhoea occurring immediately after a normal flexible sigmoidoscopy. Repeat examination confirmed the presence of proctitis. Symptoms subsided rapidly with either no treatment or steroid enemas. Eight additional patients (2.1 per cent) recorded similar problems but received no treatment and the symptoms settled spontaneously. Glutaraldehyde levels rose progressively in the rinse water after each wash cycle with 2 per cent glutaraldehyde solution. Only one possible case of proctitis (0.2 per cent) was identified from the questionnaires completed by 612 patients after changing to a washer that did not recycle the rinse water.

These observations should prompt the careful assessment of cleaning techniques. The use of washing machines that do not recycle rinse water may avoid this complication.