Published online Aug 21, 2013. doi: 10.3748/wjg.v19.i31.5103
Revised: February 8, 2013
Accepted: March 15, 2013
Published online: August 21, 2013
AIM: To compare the efficacy of different doses of sodium phosphate (NaP) and polyethylenglicol (PEG) alone or with bisacodyl for colonic cleansing in constipated and non-constipated patients.
METHODS: Three hundred and forty-nine patients, older than 18 years old, with low risk for renal damage and who were scheduled for outpatient colonoscopy were randomized to receive one of the following preparations (prep): 90 mL of NaP (prep 1); 45 mL of NaP + 20 mg of bisacodyl (prep 2); 4 L of PEG (prep 3) or 2 L of PEG + 20 mg of bisacodyl (prep 4). Randomization was stratified by constipation. Patients, endoscopists, endoscopists’ assistants and data analysts were blinded. A blinding challenge was performed to endoscopist in order to reassure blinding. The primary outcome was the efficacy of colonic cleansing using a previous reported scale. Secondary outcomes were tolerability, compliance, side effects, endoscopist perception about the necessity to repeat the study due to an inadequate colonic preparation and patient overall perceptions.
RESULTS: Information about the primary outcome was obtained from 324 patients (93%). There were no significant differences regarding the preparation quality among different groups in the overall analysis. Compliance was higher in the NaP preparations being even higher in half-dose with bisacodyl: 94% (prep 1), 100% (prep 2), 81% (prep 3) and 87% (prep 4) (2 vs 1, 3 and 4, P < 0.01; 1 vs 3, 4, P < 0.05). The combination of bisacodyl with NaP was associated with insomnia (P = 0.04). In non-constipated patients the preparation quality was also similar between different groups, but endoscopist appraisal about the need to repeat the study was more frequent in the half-dose PEG plus bisacodyl than in whole dose NaP preparation: 11% (prep 4) vs 2% (prep 1) (P < 0.05). Compliance in this group was also higher with the NaP preparations: 95% (prep 1), 100% (prep2) vs 80% (prep 3) (P < 0.05). Bisacodyl was associated with abdominal pain: 13% (prep 1), 31% (prep 2), 21% (prep 3) and 29% (prep 4), (2, 4 vs 1, 2, P < 0.05). In constipated patients the combination of NaP plus bisacodyl presented higher rates of satisfactory colonic cleansing than whole those PEG: 95% (prep 2) vs 66% (prep 3) (P = 0.03). Preparations containing bisacodyl were not associated with adverse effects in constipated patients.
CONCLUSION: In non-constipated patients, compliance is higher with NaP preparations, and bisacodyl is related to adverse effects. In constipated patients NaP plus bisacodyl is the most effective preparation.
Core tip: Colonoscopy has become the standard procedure for the diagnosis and treatment of colon diseases. Adequate bowel cleansing is essential for a high-quality effective and safe colonoscopy. In non-constipated patients, compliance is higher with sodium phosphate (NaP) preparations, and bisacodyl is related to adverse effects. In constipated patients NaP plus bisacodyl is the most effective preparation.