More Is Not Always Better: A Randomized Trial Of Low Volume Oral Laxative, Enemas, And Combination Of Both Demonstrate That Enemas Alone Are Most Efficacious For Preparation For Flexible Sigmoidoscopy

OBJECTIVES: Colon cleansing for flexible sigmoidoscopy using a standard fleet enema does not provide adequate cleansing in a significant number of patients. We tested whether the addition of a low-volume oral cleansing agent could mitigate this challenge without significantly compromising patient tolerance. Hypothesis: Oral picosulfate with magnesium citrate (P/MC) would enhance the colon cleansing of patients undergoing sigmoidoscopy, as assessed by the modified Ottawa Bowel Preparation Score. METHODS: A randomized single blinded trial comparing (1) a single dose (i.e., one sachet) of oral sodium picosulfate plus magnesium citrate (P/MC) administered the night before, (2) a single dose oral P/MC the night before plus sodium phosphate enema 1 h before leaving home, and (3) sodium phosphate enema alone 1 h before leaving home for flexible sigmoidoscopy was conducted on outpatients referred for sigmoidoscopy for symptom assessment. RESULTS: A total 120 patients were randomized to the study groups. The main indication for sigmoidoscopy was investigation of rectal bleeding (n=80). There was no significant difference in bowel cleansing quality, measured by the endoscopist blinded to preparation, between P/MC, P/MC plus enema, and enema alone as measured by the modified Ottawa Bowel Preparation Scale (P=0.34) or the Aronchick Scale (P=0.13). Both oral P/MC regimens were associated with higher incidence of nausea, abdominal pain, bloating, and interrupted sleep than enema alone (P<0.05). CONCLUSIONS: A single dose of oral P/MC administered the night before did not result in better colon cleansing for sigmoidoscopy when used alone or with an enema and was associated with more side effects (NCT 01554111).