Predictors of inadequate bowel preparation for colonoscopy

OBJECTIVE:Inadequate preparation of the bowel for colonoscopy can result in both missed pathological lesions and cancelled procedures. We looked prosp ectively at the quality of colonic preparation and evaluated potential asso ciations between specific patient characteristics and inadequate colonic pr eparation. METHODS: Data were gathered on consecutive patients presenting for colonosc opy who received either a polyethylene glycol lavage or oral sodium phospha te bowel preparation. Patient demographic and medical history information w as gathered before scheduled colonoscopy. The endoscopist evaluated the pre paration quality during the procedure. Complete data were gathered on 649 o f 714 eligible patients (90.8%). Possible predictors of inadequate colonic preparation were analyzed using univariate statistics and multivariate logi stic regression models. RESULTS: An inadequate colonic preparation was reported in 21.7% of observe d colonoscopies. Only 18% of patients with an inadequate colonic preparatio n reported a failure to adequately follow preparation instructions. A later colonoscopy starting time, a reported failure to follow preparation instru ctions, inpatient status, a procedural indication of constipation, taking t ricyclic antidepressants, male gender, and a history of cirrhosis, stroke o r dementia were all independent predictors of an inadequate colon preparati on (all p < 0.05). A procedural indication of previous polypectomy was a ne gative predictor of inadequate colonic preparation (p < 0.05). CONCLUSION: Several patient characteristics were significantly associated w ith colonic preparation quality independent of preparation type, compliance with preparation instructions, and procedure starting time. This informati on may help to identify patients at an increased risk for inadequate coloni c preparation for whom alternative preparation protocols would be appropria te. (C) 2001 by Am. Cell. of Gastroenterology.