Study design
A parallel group randomized control study was conducted throughout a period of 6 months (May–November 2019), recruiting a total of 100 patients who were referred to the gastrointestinal endoscopy and liver unit Kasr El Aini (GIELUKA) for colonoscopic examination. By means of block randomization, patients were assigned into either of the two study groups. The first group (control group, n=50) received the standard bowel preparation, two doses of PEG (120 mg of polyethylene glycol 3350 powder plus ascorbic acid), each dose added to 1L of water [13], while the second group (intervention group, n=50) recieved lubiprostone-based preparation, lubiprostone (LB) (24 μg) tablets twice daily for 2 days, then only a single dose PEG 12 h before the colonoscopy. Both groups received only clear fluids for 24 h prior to colonoscopy. A written informed consent was obtained from all patients included.
Inclusion and exclusion criteria
Adult patients (18–65 years) of both genders, with average bodyweight, were included. Patients with chronic diarrhea, known or suspected ileus, gastrointestinal obstruction, gastric retention (gastro-paresis), rectal impaction, toxic colitis, toxic megacolon, uncontrolled inflammatory bowel disease presenting in severe activity, or bowel perforation were excluded. Moreover, we excluded pregnant or breastfeeding females, patients with previous significant gastrointestinal surgery, patients with uncontrolled pre-existing electrolyte abnormalities, patients with a severe renal impairment, and patients who require emergency colonoscopy without bowel preparation.
Data collection
Demographic data were obtained from all included patients, followed by complete colonoscopic examination with intravenous propofol sedation. The degree of bowel preparation was evaluated according to Boston bowel preparation scale (BBPS). Moreover, patients’ feedback regarding tolerability and accessibility was also assessed using the 5-point Treatment Acceptability Questionnaire.
BBPS
The main objective of this scale was to evaluate specific issues that are influencing bowel preparation quality, as described by Kastenberg et al. [1]. According to the quality of the preparation, each colonic segment is graded from 0 to 3. By adding the score for all three segments, the overall score is obtained, resulting in a score between 0 and 9. A score below 4 is considered a bad preparation, resulting in a repeat procedure recommendation. The score of 5–7 is considered to be good preparation, whereas the score of 8–9 is considered to be excellent.
Statistical analysis
With a sample size of at least 78 (39/group), we had a power of 90% to assess whether the mean Boston scale was significantly higher in the lubiprostone group (~7.25 (1)) compared to its mean value in the control group of ~6.5 (1), using a two-sample means test and a significance level of 0.05. Descriptive analysis was performed using STATA 15 and was described as mean and standard deviation (SD). Categorical variables were defined as frequency and percentage. The difference between the two groups was made using the chi-square test for categorial variables and the Student t-test for quantitative variables. p-values of less than 0.05 were considered to be significant.
Ethics and consent to participate
Being conformed to the ethical guidelines of the 1975 Declaration of Helsinki and its later amendments revised in Seoul, Korea, October 2008 as reflected in previous approval by the institution’s human research committee, the study protocol was approved by the research ethical committee of the endemic medicine department and the institutional review board of the faculty of medicine, Cairo University. All patients had signed a written informed consent before the start of any procedure related to the study. The personal data were concealed and replaced by numbers for patient’s confidentiality.