Objective: To compare the efficacy and patient acceptance of an oral high dose of senna to conventional polyethylene glycol-electrolyte lavage solution (PEG-ES) in adults undergoing elective colonoscopy.
Methods: Consecutive outpatients referred for elective colonoscopy were prospectively randomly assigned to receive, the day before the procedure, either 24 tablets of 12 mg senna, divided into two doses at 1 p.m. and 9 p.m. (senna group, n=191), or standard 4-L PEG-ES (PEG-ES group, n=92). The overall quality of colon cleansing (primary outcome measure) and cleansing in the right colon were evaluated using the Aronchick scoring scale (1=excellent to 4=inadequate) by the investigator/endoscopist who was blinded to the treatment assignment. Patient acceptance and the safety of the preparation were assessed by a nurse, using a structured questionnaire covering compliance with the dosing, overall tolerance of the preparation (1=none or mild discomfort to 4=severely distressing), and adverse events.
Results: The quality of colon cleansing, overall tolerance of the preparation, and compliance were significantly better with senna; overall cleansing was excellent or good in 90.6% of patients in the senna group and in 79.7% in the PEG-ES group (p= 0.003). The percentage of procedures rescheduled because of insufficient colon cleansing was 7.3% in the PEG-ES group and 2.6% in the senna group (p=0.035). Multivariate logistic regression modeling showed the PEG-ES preparation as negative independent predictor of unsuccessful bowel cleansing. The incidence of adverse reactions was similar in the two groups; patients who received senna experienced significantly less nausea and vomiting, but more abdominal pain.
Conclusions: An oral high dose of senna is a valid alternative to standard PEG-ES for outpatient colonoscopy preparation.