Authors: Moath Hattab, Mohammed Shakhshir, Carmel Khalil, Raw’a Mletat, Razan Rabi, Raya Yassin, Malek Hejaz, Mohammed M. Hajhamad
Categories: Research, Colonoscopy/methods, Patient Education/Methods, Mobile applications
Source: BMC Gastroenterology
Authors: Moath Hattab, Mohammed Shakhshir, Carmel Khalil, Raw’a Mletat, Razan Rabi, Raya Yassin, Malek Hejaz, Mohammed M. Hajhamad
Inadequate bowel preparation (BP) compromises colonoscopy quality, efficiency, and patient outcomes. We evaluated whether a resource-light multimodal educational package improves BP adequacy compared with standard instructions.
We conducted a prospective, single-blinded, parallel-group, single-center randomized clinical trial in which adults scheduled for elective colonoscopy were randomized 1 to standard education (leaflet) or enhanced education (face-to-face counseling, 6-minute video, illustrated booklet, smartphone-app reminders). The primary outcome was adequate preparation, defined as a composite criterion of total Boston Bowel Preparation Scale (BBPS) ≥ 6 with all three colonic segments (right, transverse, left) scoring ≥ 2. Secondary outcomes included total BBPS ≥ 6 irrespective of segment scores, segmental BBPS ≥ 2, mean segmental and total BBPS, cecal intubation success and times, withdrawal time, adverse effects, compliance, anxiety, and satisfaction. Exploratory multivariable logistic regression examined clinical predictors of adequate BP.
A total of 150 patients were analyzed (75 per group). Using the composite primary definition, adequate preparation was achieved in 60/75 (80.0%) in the intervention group versus 49/75 (65.3%) in controls (risk ratio [RR] 1.22; 95% CI 1.00–1.50; p = 0.047; number-needed-to-treat ≈ 7). For total BBPS ≥ 6 irrespective of segment scores, adequacy was 85.3% versus 70.7% (RR 1.21; 95% CI 1.02–1.44; p = 0.033). Segmental BBPS ≥ 2 favored the intervention in the left (90.7% vs. 78.7%; p = 0.044) and transverse colon (92.0% vs. 80.0%; p = 0.037), with a concordant but non-significant trend in the right colon. Mean total BBPS (6.79 ± 1.55 vs. 6.11 ± 1.72; p = 0.012) and mean right and transverse segment scores were also higher with the intervention, indicating a global shift toward better cleanliness. Cecal intubation success (98.7% in both groups), cecal intubation and withdrawal times, self-reported compliance, adverse effects, anxiety scores, and satisfaction did not differ meaningfully between groups. In exploratory adjusted analyses, the intervention remained positively associated with adequacy (adjusted odds ratio 1.89; 95% CI 0.86–4.26), and polypharmacy emerged as an independent negative predictor (0.42; 95% CI 0.18–0.96).
A brief, low-cost multimodal education strategy improved bowel preparation quality, increasing the proportion of patients achieving guideline-relevant BBPS adequacy without adversely affecting patient experience or procedure times. Implementation in routine practice may help endoscopy units move closer to recommended quality benchmarks and reduce the burden of inadequate-prep–related repeat examinations.
This clinical trial was registered on ClinicalTrials.gov (Identifier: NCT07093099). And was registered retrospectively on July 29, 2025, due to being the first RCT in our center and there was an administrative error in early registration, but IRB approval letters are available to confirm strict adherence to the original protocol. The Registration is available at https://clinicaltrials.gov/study/NCT07093099.
The online version contains supplementary material available at 10.1186/s12876-025-04569-5.
Colonoscopy is the gold standard for colorectal cancer screening and diagnosis of various gastrointestinal disorders. The quality of colonoscopy depends heavily on adequate mechanical bowel preparation (MBP), which ensures optimal visualization of the colonic mucosa. Poor MBP is associated with lower adenoma detection rates, increased procedure times, higher healthcare costs, and the need for repeat procedures. Despite standard bowel preparation guidelines, studies indicate that up to 30% of MBPs remain inadequate, leading to suboptimal clinical outcomes [1]. The Boston Bowel Preparation Scale (BBPS) provides a validated, segment‑based assessment of cleanliness and correlates with adenoma detection. An examination is generally considered adequate when each of the three colonic segments scores ≥ 2 and the total BBPS is ≥ 6 [2–4]. Current US-Multi-Society Task Force guidance recommends > 85% of colonoscopies achieve adequate preparation to minimize missed lesions. Nevertheless, 15–30% of colonoscopies still have inadequate cleansing, particularly among high-risk patients, advanced age, male sex, low education levels, previous abdominal surgery, chronic constipation, comorbidities like diabetes, and those taking constipating medications [5]. Observational evidence showed that inadequate prep is linked to prolonged procedure time, needing repeat colonoscopies, and higher interval-cancer risk [6]. Educational interventions - including videos, booklets, mobile apps, and lengthier more detailed person-to-person explanations – have shown a promise in improving preparation quality by improving adherence behavior or improved BBPS scores [7]. We evaluated a targeted, low-cost multimodal educational package, that combines face‑to‑face counselling, printed and digital media, and automated reminders, hypothesizing it would increase the proportion of adequate preparation relative to current standard leaflets.
This study was a prospective, randomized, single-blinded, parallel-group superiority trial conducted at Rafidia Surgical Hospital in Palestine. Conducted from December 2020 to June 2021.
Eligible participants are adults (≥ 18 years) undergoing elective colonoscopy from December 2020 to June 2021 who accepted the invitation to participate. Exclusions: allergy/intolerance to bowel preparation agents, pregnancy, severe comorbid conditions, severe organ failure, or inability to consent. The institutional review board approved the protocol; all participants gave written informed consent.
Participants were randomized in a 1 ratio using computer‑generated block randomization (concealed in sequentially numbered opaque envelopes) to Control A or Intervention B. Endoscopists assessing MBP quality (bowel cleanliness) via BBPS were blinded to group assignments to reduce observer bias.
This single-center trial was primarily feasibility-driven. The planned enrollment was 150 patients, based on annual colonoscopy volume and logistic capacity. Under the assumption that 70% of standard-care patients would achieve adequate preparation and that the intervention could improve this to ∼85%, this sample size provides approximately 80% power to detect a 15-percentage-point absolute difference at a two-sided α of 0.05. These assumptions were informed by previous educational-intervention studies and guideline targets for BBPS adequacy.
All patients in both groups underwent a standardized split-dose bowel preparation combining a polyethylene glycol (PEG)–electrolyte solution (Meroken^®^) with stimulant laxative tablets (Laxidin^®^). On the day before colonoscopy, patients were instructed to eat a low-residue breakfast and then follow a clear-liquid diet, avoiding red or purple liquids. At 00 they took five Laxidin tablets and started drinking the PEG solution prepared according to the manufacturer’s instructions (Meroken^®^ dissolved in 3 L of water), ingesting approximately 250 mL every hour from 00 until midnight. The remaining 1 L of PEG solution was kept refrigerated and consumed at 00 on the morning of the procedure. A second dose of five Laxidin tablets was taken at 00 on the evening before colonoscopy. Patients were allowed clear fluids during the preparation and were kept strictly nil per os after 00 on the day of colonoscopy.
Standard Education Group (Control/A):
Enhanced Education Group (Intervention/B):
Primary: adequate bowel preparation defined as a composite BBPS total BBPS ≥ 6 with all three colon segments (right, transverse, left) scoring ≥ 2 [2–4].
Secondary: BBPS (0–3), cecal‑intubation success and time, withdrawal time, satisfaction with preparation and with colonoscopy (0–10 scales), and Anxiety on colonoscopy day. The pre-colonoscopy and colonoscopy day questionnaires are provided with the supplementary files. And patient anxiety was assessed using the 5-item State–Trait Anxiety Inventory short form (STAI-5) [8].
Given that age and other clinical factors may influence bowel preparation quality, we performed an exploratory multivariable logistic regression with adequate bowel preparation (composite primary total BBPS ≥ 6 with all three segments ≥ 2) as the dependent variable, including group (intervention vs. control), age > 65 years, prior abdominal/pelvic surgery, constipation, and polypharmacy as covariates².
SPSS (version 25) and R (version 4.5.1) were used. Continuous variables were summarized as mean ± standard deviation and compared between groups using independent-samples t-tests when distributions were approximately normal, or Mann–Whitney U tests otherwise; ordinal variables were analyzed with Mann–Whitney U tests. Categorical variables were summarized as counts and percentages and compared using χ² tests (or Fisher’s exact test when expected cell counts were < 5). All tests were two-sided with α = 0.05. For binary outcomes, we calculated risk ratios (RRs) with 95% confidence intervals and number-needed-to-treat (NNT = 1/absolute risk difference).
Between December 2020 and June 2021, 150 adults were randomized into two groups, a standard instructions group (Control/A, n = 75) and a multifaceted enhanced-education package group (Intervention/B, n = 75). All the participants completed colonoscopy and were included in the analysis.
The control arm was older (mean 54.8 ± 17.4 years vs. 48.8 ± 16.4 years; t = 2.20, df ≈ 148, p = 0.03) and therefore included a higher proportion of patients aged > 65 years (36.0% vs. 14.7%; χ² = 7.93, p = 0.005). No significant group differences were observed for sex ratio, prior abdominal surgery, constipation, polypharmacy, BMI class, socioeconomic status, or education level (all p > 0.10). All baseline demographic and clinical characteristics of the study population are shown in (Table 1).
Table 1Baseline demographic and clinical characteristics of the study populationBaseline Demographic and Clinical Characteristics of the Study PopulationContinuous Variables VariableMean (SD)Mean (SD)Control (A)Intervention (B)Age54.83 (17.38)48.77 (16.4)Weight78.5 (16.34)78.0 (20.09)Height166.5 (9.26)165.2 (12.19)BMI28.31 (5.36)28.85 (8.27)Categorical VariablesVariablen (%)n (%)Control (A)Intervention (B)GenderMale43 (57.3%)44 (58.7%)Female37 (42.7%)31 (41.3%)History of previous abdominal/pelvic surgeries36 (48.0%)35 (46.7%)Constipation over 3 days30 (40.0%)26 (34.7%)Age more than 6527 (36.0%)11 (14.7%)Constipating drugs (opioids, TCAs, calcium antagonists)1 (1.3%)2 (2.7%)Polypharmacy31 (41.3%)31 (41.3%)Previous Hospitalization53 (70.67%)36 (48%)Comorbidity (stroke, dementia, Parkinson)1 (1.3%)6 (8.0%)Cirrhosis0 (0.0%)0 (0.0%)BMI ClassUnderweight3 (4.0%)3 (4.0%)Normal21 (28.0%)22 (29.3%)Overweight25 (33.3%)24 (32.0%)Obese26 (34.7%)26 (34.7%)History of CVA3 (4.0%)6 (8.0%)IBD2 (2.7%)1 (1.3%)Educational levelNever went to school3 (4.0%)2 (2.7%)School 9th grade and below23 (30.7%)32 (42.7%)Finished high school25 (33.3%)19 (25.3%)Collage/University22 (29.3%)21 (28.0%)Higher education2 (2.7%)1 (1.3%)Low socioeconomic state52 (69.3%)45 (60%)
On the day of colonoscopy, self-reported compliance was high and broadly comparable between the two groups. Adherence to a low-fiber diet the day before was “yes, totally” in 71/75 (94.7%) of both control (A) and intervention (B) patients (partial 3/75 [4.0%] vs. 2/75 [2.7%]; none 1/75 [1.3%] vs. 2/75 [2.7%]). Completion of the polyethylene-glycol solution (“Meroken”) was similar (all 57/75 [76.0%] vs. 56/75 [74.7%]; half–two-thirds 15/75 [20.0%] vs. 17/75 [22.7%]; < half 2/75 [2.7%] vs. 2/75 [2.7%]; none 1/75 [1.3%] vs. 0/75). Most patients followed the intended split schedule, taking the solution each hour over six hours (66/75 [88.0%] vs. 71/75 [94.7%]); fewer stretched doses to every 2–3 h (6/75 [8.0%] vs. 4/75 [5.3%]) or took it once daily (3/75 [4.0%] vs. 0/75). Hydration was suboptimal in both only 29/75 (38.7%) vs. 24/75 (32.0%) reported drinking ≥ 3 L of water. Use of the stimulant laxative (“Laxidin”) was high and comparable (mean ± SD tablets 9.27 ± 2.42 vs. 9.83 ± 1.18). Side effects were likewise nausea in 36/75 (48.0%) vs. 37/75 (49.3%), vomiting 18/75 (24.0%) vs. 12/75 (16.0%), abdominal pain 33/75 (44.0%) vs. 38/75 (50.7%), urinary urgency 73/75 (97.3%) vs. 69/75 (92.0%), and bad taste 32/75 (42.7%) vs. 40/75 (53.3%). Satisfaction with the Preparation (0–10) was high and nearly identical (mean ± SD 7.75 ± 2.65 vs. 7.79 ± 2.12). Pre-procedure anxiety (STAI-5) distributions were closely matched across items (Fig. 1) feeling calm “moderately/very much” in 59/75 (78.7%) vs. 56/75 (74.7%) and “not at all” 3/75 (4.0%) vs. 7/75 (9.3%); feeling tense “not at all” in 29/75 (38.7%) vs. 29/75 (38.7%) and “very much” 8/75 (10.7%) in both; feeling upset “not at all” in 33/75 (44.0%) vs. 33/75 (44.0%); being relaxed “moderately/very much” in 55/75 (73.3%) vs. 51/75 (68.0%); being content “moderately/very much” in 54/75 (72.0%) vs. 56/75 (74.7%); and being worried “not at all” in 32/75 (42.7%) vs. 27/75 (36.0%). Post-colonoscopy attitudes were favorable in both willingness to undergo the procedure again if needed was “agree/strongly agree” in 60/75 (80.0%) vs. 62/75 (82.7%) (neutral 5/75 [6.7%] vs. 7/75 [9.3%]; disagree/strongly disagree 10/75 [13.3%] vs. 6/75 [8.0%]). Satisfaction with the colonoscopy itself remained high and comparable (mean ± SD 8.43 ± 1.78 vs. 8.64 ± 1.59). Full list of variables is listed in (Table 2).
Fig. 1STAI-5 questionnaire response distribution between the two groups
Table 2Colonoscopy day evaluationColonoscopy DayVariableControl (A)Intervention (B)Compliance Did you follow on fibers the day before?Yes totally71 (94.7%)71 (94.7%)Partially3 (4.0%)2 (2.7%)No1 (1.3%)2 (2.7%) Have you finished Meroken?Yes, all of it57 (76.0%)56 (74.7%)Half to two thirds15 (20.0%)17 (22.7%)Less than half2 (2.7%)2 (2.7%)I did not take it1 (1.3%)0 (0.0%) How did you take Meroken?Each hour for 6 h66 (88.0%)71 (94.7%)Each two-three hours6 (8.0%)4 (5.3%)Once daily3 (4.0%)0 (0.0%) Drank 3 L of water or more?Yes29 (38.7%)24 (32.0%)No46 (61.3%)51 (68.0%) How many pills of Laxidin did you take?Mean (SD)9.27 (2.42)9.83 (1.18)Side Effects and Satisfaction NauseaYes36 (48.0%)37 (49.3%)No39 (52.0%)38 (50.7%) VomitingYes18 (24.0%)12 (16.0%)No57 (76.0%)63 (84.0%) Abdominal painYes33 (44.0%)38 (50.7%)No42 (56.0%)37 (49.3%) Urinary urgencyYes73 (97.3%)69 (92.0%)No2 (2.7%)6 (8.0%) Bad tasteYes32 (42.7%)40 (53.3%)No43 (57.3%)35 (46.7%) how satisfied are you with your preparation for colonoscopy and the solution you went through (0–10)Mean (SD)7.75 (2.651)7.79 (2.120)Anxiety STAI-5 Questionnaire I feel CalmVery much12 (16.0%)15 (20.0%)moderately47 (62.7%)41 (54.7%)little13 (17.3%)12 (16.0%)Not at all3 (4.0%)7 (9.3%) I feel TenseVery much8 (10.7%)8 (10.7%)moderately20 (26.7%)22 (29.3%)little18 (24.0%)16 (21.3%)Not at all29 (38.7%)29 (38.7%) I feel UpsetVery much8 (10.7%)9 (12.0%)moderately14 (18.7%)14 (18.7%)little20 (26.7%)19 (25.3%)Not at all33 (44.0%)33 (44.0%) I am RelaxedVery much11 (14.7%)15 (20.0%)moderately44 (58.7%)36 (48.0%)little18 (24.0%)20 (26.7%)Not at all2 (2.7%)4 (5.3%) I am ContentVery much16 (21.3%)17 (22.7%)moderately38 (50.7%)39 (52.0%)little17 (22.7%)13 (17.3%)Not at all4 (5.3%)6 (8.0%) I am WorriedVery much13 (17.3%)10 (13.3%)moderately14 (18.7%)18 (24.0%)little16 (21.3%)20 (26.7%)Not at all32 (42.7%)27 (36.0%)Post Colonoscopy Would undergo colonoscopy again if neededStrongly agree17 (22.7%)12 (16.0%)Agree43 (57.3%)50 (66.7%)neutral5 (6.7%)7 (9.3%)Disagree9 (12.0%)5 (6.7%)Strongly disagree1 (1.3%)1 (1.3%) How satisfied are you with your Colonoscopy? 1–10Mean (SD)8.43 (1.780)8.64 (1.591)
Using the primary composite definition (total BBPS ≥ 6 and all three segments BBPS ≥ 2), adequate preparation was achieved in 60/75 (80.0%) patients in the intervention group and 49/75 (65.3%) in the control group (Fig. 2). This corresponds to a 14.7-percentage-point absolute increase and a risk ratio (RR) of 1.22 (95% CI 1.00–1.50; p = 0.047), yielding an approximate number-needed-to-treat of 7 to prevent one inadequate preparation.
Fig. 2Segmental and total Boston Bowel Preparation Scale (BBPS) scores by group. And Forest plot of BBPS segment and total score differences (Intervention minus Control) with 95% Cis
BBPS ≥ 6 irrespective of segment scores was observed in 64/75 (85.3%) patients in the intervention arm and 53/75 (70.7%) in the control arm (RR 1.21, 95% CI 1.02–1.44; p = 0.033). When each colon segment was analyzed dichotomously using the BBPS ≥ 2 threshold segmental adequacy was significantly higher with the intervention in the left and transverse Left 68/75 (90.7%) vs. 59/75 (78.7%); RR 1.15, 95% CI 1.00–1.32; p = 0.044. Transverse 69/75 (92.0%) vs. 60/75 (80.0%); RR 1.15, 95% CI 1.01–1.31; p = 0.037. In contrast, the proportion of patients with adequate right-colon cleansing was 64/75 (85.3%) in the intervention group and 58/75 (77.3%) in the control group (RR 1.10, 95% CI 0.95–1.29; p = 0.211), a non-significant but concordant trend. Overall, four of the five dichotomous outcomes plotted in Fig. 2 (composite adequacy, left-colon BBPS ≥ 2, transverse-colon BBPS ≥ 2, and total BBPS ≥ 6) showed statistically significant improvement with the multimodal education package, while right-colon BBPS ≥ 2 showed a similar direction of effect but did not reach statistical significance.
Complementing these binary thresholds, Fig. 3 summarizes the mean BBPS scores (± SD) for each segment and for the total score. These analyses assess the overall distribution of cleanliness scores, rather than the proportion of patients above or below a specific adequacy cut-off. The mean total BBPS was higher in the intervention group (6.79 ± 1.55 vs. 6.11 ± 1.72; p = 0.012), indicating a global shift towards better bowel cleanliness. Segmentally, the right colon scored 2.20 ± 0.75 versus 1.97 ± 0.70 (mean difference + 0.23; 95% CI + 0.02 to + 0.44; p = 0.034), the transverse colon 2.33 ± 0.62 versus 2.04 ± 0.71 (mean difference + 0.29; 95% CI + 0.07 to + 0.51; p = 0.010), and the left colon 2.25 ± 0.62 versus 2.09 ± 0.72 (mean difference + 0.16; 95% CI − 0.05 to + 0.37; p = 0.18). (Table 3), (Fig. 3)
Fig. 3Forest plot showing the effect of the multimodal education intervention on bowel preparation quality compared with standard education. Outcomes include overall adequacy (all three segments BBPS ≥ 2 and total BBPS ≥ 6), segmental adequacy (right, left, and transverse colon BBPS ≥ 2), and total BBPS ≥ 6, in 75 patients per group. Values are expressed as risk ratios (RRs) with 95% confidence intervals; RRs > 1 favor the intervention group. P-values are from χ² tests for between-group differences
Table 3Evaluation by endoscopist on bowel Preparation adequacy on colonoscopy dayEvaluation by EndoscopistQuantitative Variables VariableGroupnMeanSDSEM BBSS in right colon (1–3)A751.970.6970.080B752.200.7530.087 BBSS in left colon (1–3)A752.090.7200.083B752.250.6170.071 BBSS in transverse colon (1–3)A752.040.7060.082B752.330.6220.072 BBSS TotalA756.111.7210.199B756.791.5530.179 Withdrawal timeA759.889.9191.145B7510.096.9030.797 Cecal intubation rateA7521.2811.5471.333B7518.558.8001.016Qualitative Variables VariableAB Reached cecumYes74 (98.7%)74 (98.7%)No1 (1.3%)1 (1.3%)
While the left colon showed statistically significant improvement when assessed as the proportion of patients achieving BBPS ≥ 2, the difference in mean score did not reach significance, likely reflecting ceiling effects in a segment that was already relatively well cleansed in both arms. In the right colon, the converse pattern was mean BBPS scores were significantly higher with the intervention, although the proportion achieving BBPS ≥ 2 did not differ significantly. Together, these patterns suggest that the intervention improved not only the probability of crossing adequacy thresholds but also cleanliness within the adequate range (for example, shifting scores from 2 to 3) in some segments.
Cecal intubation and withdrawal metrics were similar between groups. Cecal intubation was successful in 74/75 patients (98.7%) in both the control and intervention arms. Mean cecal intubation time was 21.28 ± 11.55 min in the control group and 18.55 ± 8.80 min in the intervention group, while mean withdrawal time was 9.88 ± 9.92 versus 10.09 ± 6.90 min, respectively. None of these differences reached statistical significance, suggesting that the improvement in bowel cleanliness did not translate into measurable changes in standard colonoscopy performance times in this sample. (Table 3).
Because age and clinical risk factors may influence bowel preparation quality, we performed a multivariable logistic regression with adequate BP (BBPS ≥ 2 in each segment and total ≥ 6) as the dependent variable and group (intervention vs. control), age > 65 years, history of abdominal/pelvic surgery, constipation ≥ 3 days, and polypharmacy as covariates. In this model, the intervention remained associated with higher odds of adequate preparation, but this did not reach statistical significance (adjusted OR 1.89; 95% CI 0.86–4.26). Age > 65 years showed a non-significant trend towards reduced adequacy (OR 0.47; 95% CI 0.18–1.18). Polypharmacy was an independent negative predictor of adequate preparation (OR 0.42; 95% CI 0.18–0.96), whereas prior surgery (OR 0.82; 95% CI 0.38–1.78) and constipation (OR 1.07; 95% CI 0.48–2.50) were not significantly associated with the outcome.
In patients aged > 65 years, adequate preparation increased from 55.6% (15/27) in the control group to 81.8% (9/11) in the intervention group (RR 1.84; 95% CI 1.04–3.25). However, re-analysis using Fisher’s exact test to account for small cell counts (only 2 inadequately prepared patients in the intervention arm) showed that this difference was no longer statistically significant (p = 0.12; exact odds ratio 4.56; 95% CI 0.69–53.36). For patients with prior abdominal surgery, bowel preparation adequacy rose from 72.2% to 88.6% (RR 1.23), but this difference also did not reach statistical significance (p = 0.11). Subgroup analyses by other risk factors (constipation, polypharmacy, low socioeconomic status, diabetes, smoking status) showed consistently higher adequacy rates in the intervention arm, but confidence intervals were wide and formal interaction testing was not powered.
This randomized trial demonstrates that a concise, resource-light, multimodal education package, combining face-to-face counselling, a 6-minute video, a pictorial booklet, and a reminder-based smartphone app, significantly improves bowel preparation quality compared with standard written instructions alone. Using the composite primary definition of adequacy (total BBPS ≥ 6 with all three segments scoring ≥ 2), adequacy increased from 65.3% in the control group to 80.0% in the intervention group (RR 1.22; 95% CI 1.00–1.50; p = 0.047), corresponding to a number-needed-to-treat of approximately 7. When adequacy was defined more simply as total BBPS ≥ 6 irrespective of segmental scores, 85.3% of patients in the intervention arm and 70.7% in the control arm met the threshold (RR 1.21; 95% CI 1.02–1.44; p = 0.033). Thus, the intervention both increased the proportion of patients meeting guideline-oriented adequacy criteria and moved a substantial fraction above a widely used global BBPS cut-off.
Dichotomous segmental analyses and mean score comparisons provide complementary perspectives on how the intervention shifted bowel cleanliness. When applying a BBPS ≥ 2 threshold per segment, the intervention significantly increased the proportion of patients with adequate cleansing in the left and transverse colon, and showed a concordant, though non-significant, trend in the right colon. In contrast, analyses of the mean BBPS scores demonstrated statistically significant improvements in the right and transverse colon and in the total BBPS, with a non-significant trend in the left colon. This apparent discrepancy is readily explained by the different aspects of performance captured by each metric. In the left colon, most patients in both groups already had scores ≥ 2, so a further improvement in the average score (for example, from 2 to 3) had limited impact on the proportion crossing the adequacy threshold and was susceptible to ceiling effects. In the right colon, the reverse pattern was mean scores were higher in the intervention arm, but many patients in both groups were already at or above the BBPS ≥ 2 cut-off, so the gain was more visible in the continuous score than in the binary “adequate/inadequate” outcome. Taken together, these findings suggest that the multimodal education package not only increased the probability of achieving an adequate preparation according to guideline-relevant thresholds, but also improved cleanliness within the adequate range in several segments.
Because the control arm was older and included a higher proportion of patients over 65 years, we explored potential confounding using multivariable logistic regression. In a model with total BBPS ≥ 6 as the dependent variable and including group, age > 65 years, previous abdominal/pelvic surgery, constipation, and polypharmacy as covariates, the intervention retained a positive association with adequacy (adjusted OR 1.89; 95% CI 0.86–4.26), although this did not reach conventional statistical significance. Age > 65 years showed a trend toward reduced adequacy (OR 0.47; 95% CI 0.18–1.18), consistent with prior literature identifying older age as a negative predictor of bowel prep quality, but again with wide confidence intervals in this single-center trial. Polypharmacy emerged as a clear and consistent negative predictor (OR 0.42; 95% CI 0.18–0.96), whereas prior surgery and constipation were not significantly associated with the outcome. An extended sensitivity model including additional binary risk-factor flags (male sex, low educational level, low socioeconomic status, obesity) yielded similar point estimates for the intervention and age, and again highlighted polypharmacy as a potential high-risk feature. Overall, the adjusted analyses support the direction of benefit seen in the unadjusted comparisons, but also indicate that this feasibility-sized study was underpowered to definitively establish an independent effect of the intervention after adjusting for multiple correlated risk factors.
Subgroup analyses provide additional clinical context but must be interpreted cautiously. In patients aged > 65 years, adequacy improved from 55.6% to 81.8% (RR 1.84; 95% CI 1.04–3.25) in crude analyses; however, when re-analyzed using Fisher’s exact test to account for small cell counts (only two inadequately prepared patients in the intervention arm), this difference was no longer statistically significant (p = 0.12; exact OR 4.56; 95% CI 0.69–53.36). A similar pattern was seen in patients with prior abdominal surgery, where adequacy increased from 72.2% to 88.6% (RR 1.23; p = 0.11). Trends favoring the intervention were also observed in subgroups defined by constipation, diabetes, smoking, and low socioeconomic status, but confidence intervals were wide and formal interaction testing was not powered. These exploratory analyses are consistent with a broadly beneficial intervention whose effect is directionally similar across risk strata, but they do not justify strong claims about preferential benefit in any particular subgroup.
Our findings align well with prior trials and meta-analyses of educational interventions for colonoscopy preparation. A meta-analysis reported a pooled RR of ~ 1.22 for adequate preparation with enhanced education, which is almost identical to the RRs we observed for both our composite and total BBPS ≥ 6 outcomes [7]. Individual RCTs have shown similar absolute Park et al. improved adequate prep from 78% to 92% using a brief video intervention [9], and Van der Zander et al. reported higher right-colon cleanliness scores with a tailored smartphone application [1]. Our trial extends this evidence to an Arabic-speaking, middle-income setting using a pragmatic multimodal package that combines these elements (face-to-face counselling, video, printed material, and app reminders) within routine hospital practice.
Although self-reported adherence to the low-residue diet and completion of the PEG solution appeared similar between groups, the multimodal package may have improved the quality and timing of adherence rather than crude completion alone. By reinforcing key messages through Arabic (the patients’ native language), patient-friendly language, visual aids, and app-based reminders, patients were more likely to take doses at the correct intervals and adjust their behavior when difficulties arose, leading to cleaner preparations without major changes in reported compliance.
Despite better preparation in the intervention group, cecal-intubation success and typical time metrics (cecal intubation time and withdrawal time) were similar between groups. This likely reflects the high baseline performance of experienced endoscopists, who can often compensate for moderate variability in bowel cleanliness, and the fact that our intervention mainly shifted patients from marginally adequate to clearly adequate, rather than rescuing large numbers from severely inadequate preparation. Patient-reported experience was also side-effect profiles, pre-procedure anxiety levels, satisfaction with the preparation regimen, and willingness to undergo colonoscopy again were all comparable between groups. In other words, the multimodal educational package improved objective cleanliness without adding noticeable burden or discomfort from the patient’s perspective. In addition, self-reported compliance is prone to social desirability bias, patients may overstate how closely they followed instructions to avoid disappointing their doctor, and the enhanced education may have increased both their awareness of the consequences of poor preparation and their sense of responsibility, leading to more genuine adherence than questionnaire responses alone suggest.
The identification of polypharmacy as an independent negative predictor in our multivariable analysis is clinically important. Patients on multiple medications often have complex comorbidities, may be taking constipating agents, and may find timing and fasting requirements more challenging. Our data suggest that these patients are at heightened risk of suboptimal preparation even when an enhanced educational package is used. In practice, such individuals might benefit from additional strategies, such as closer pre-procedure counselling, tailored medication adjustments, or intensified bowel prep regimens. Future trials could specifically target polypharmacy and other high-risk features to test layered interventions on top of educational support.
Finally, our use of both binary adequacy thresholds and mean BBPS scores highlights the value of reporting bowel preparation quality in multiple, complementary ways. Binary outcomes are intuitive and directly aligned with guideline targets and clinical decision points (e.g. whether to repeat a colonoscopy early), whereas mean scores capture shifts in the overall distribution of cleanliness, including improvements within the “adequate” range that may still be clinically meaningful. In this trial, both types of analyses pointed in the same direction, reinforcing the robustness of the observed benefit.
Strengths of our study include that it was randomized, blinded outcome assessment, and focuses on a practical and easy-to-implement intervention, and widely accessible and acceptable.
Limitations included that the sample size was based on feasibility, potentially underpowering detection of some secondary outcomes. We also used a multimodal educational package; thus, we can’t be sure which modalities were more or less effective.
Our study demonstrates that a low-cost, multimodal educational intervention can significantly improve bowel preparation adequacy, especially with high-risk patients. These patients had an improved BBPS score in the right and transverse colon, and the total BBPS score. These improvements were achieved without compromising patient satisfaction, and may enhance the overall quality and cost-efficiency of colonoscopies, and decreasing the need for repeat colonoscopies due to inappropriate preparation. Broader implementation of such interventions, tailored to local context (language, educational level, etc.) could achieve this.
In summary, a brief, multimodal educational intervention significantly improved bowel preparation quality for colonoscopy, increasing the proportion of patients meeting a stringent composite adequacy definition and enhancing both segmental and total BBPS scores, without adversely affecting patient experience or procedural performance metrics. The direction and magnitude of benefit were consistent with prior literature, and exploratory analyses suggest that patients with polypharmacy may be at particular risk for inadequate preparation despite standard instructions.
Given its low cost, scalability, and acceptability, this multimodal approach is a promising strategy for endoscopy units seeking to improve preparation quality and move closer to guideline-recommended adequacy targets. Future studies should evaluate the intervention in larger, multi-center cohorts; formally assess its impact on adenoma and serrated lesion detection; and test tailored enhancements for high-risk groups such as older adults and patients on multiple medications.
Supplementary Material 1.
Supplementary Material 2.
Supplementary Material 3.