Ask an answerable question (PICO)：
Colorectal cancer has the highest incidence among all cancer types in Taiwan. If the fecal occult blood test is positive, further colonoscopy is recommended. The level of bowel cleansing directly affects the quality of colonoscopy examination. To achieve good bowel cleansing, the examinee needs to take bowel preparation drugs and follow a low-residue diet. However, many examinees cannot tolerate prolonged hunger and are dissatisfied and resistant to the preparation before colonoscopy. Therefore, in response to the needs of examinees, empirical nursing steps are taken to investigate whether a low-residue diet only one day before colonoscopy affects the level of bowel cleansing.
The Method and Analysis of Literature Review：
In response to this, a clinical question was formulated and PICO was established. Boolean logic was used to combine the keywords of P, I, C, and O with "OR" and "AND" to search five databases. The search was limited to randomized controlled trials and systematic reviews. A total of 98 articles were identified, and after screening the titles and abstracts, 95 articles were excluded due to duplication, lack of relevance to the topic, or other interventions. Finally, 3 high-quality randomized controlled trials with strong evidence were selected for critical appraisal.
Critical Appraisal：
The Critical Appraisal Skills Programme (CAPS) 2020 version of the Randomized Controlled Trials (RCT) checklist was used as the article appraisal tool, and validity, importance, and clinical applicability were evaluated. The Oxford Centre for Evidence-Based Medicine (CEBM) levels of evidence (2011) were used to evaluate the level of evidence, which was determined to be Level 2 therapy. The first article studied patients aged 18 years and older who underwent colonoscopy, and the intervention was a low-residue diet for one day, while the control group received a low-residue diet for two days. The Boston Bowel Preparation Scale (BBPS) was used to measure the level of bowel cleanliness, and the results showed no statistically significant difference between the two groups. The secondary outcome indicated that the one-day low-residue diet was more readily accepted by the patients. The second and third article studied outpatients aged 18 years and older undergoing colonoscopy to compare whether a three-day low-residue diet improved bowel cleansing quality compared to a one-day low-residue diet. The study used chi-square statistics for categorical variables and t-tests for continuous variables to compare the two groups. The conclusion was that the three-day low-residue diet preparation was not statistically different from the one-day low-residue diet preparation.
Clinical Application of Evidence：
Based on the results of the literature, we examine the effect of a 1-day low residue diet (LRD) versus a 2-day LRD on bowel preparation and patient satisfaction among 26 individuals aged 50 to 80 years who undergo painless colonoscopy. Participants will be conveniently sampled and randomized to either the 1-day(11 subjects) or 2-day(15 subjects) LRD group. All participants will receive the same bowel preparation, which will be taken in segments, and colonoscopy will be performed in the morning. The colonoscopy results and bowel cleanliness will be graded using the Aronchick scale and reported by the physician. The evaluation will compare the difference in bowel cleanliness between the two groups and the satisfaction level with the low residue diet before colonoscopy.
Evaluation of Effectiveness：
From November 26th to December 4th, 2022, the study compared the ratio of individuals with excellent or good colon cleansing efficacy between two groups: the one-day low-residue diet (LRD) group with a rate of 90.9% and the two-day LRD group with a rate of 86.7%. Neither did it reach the statistical significance(p= 0.77), nor it proceed adverse event. The study also compared the satisfaction levels of the two groups with regards to low-fiber diet control before the colonoscopy, with an average score of 4.91 for the one-day LRD group and 4.27 for the two-day LRD group. It reached the statistical difference(P<0.01), and demonstrate that the intervention enhances the satisfaction of the subjects at preparation phase.
Conclusions and Recommendations：
Clinical evidence has confirmed that shortening the low-fiber diet control period to one day is feasible without compromising the quality of colon cleansing. This approach can effectively reduce discomfort associated with diet control and improve patient satisfaction with the preparation process before colonoscopy. These results may provide a useful reference for healthcare providers in other clinical settings when managing health checkups.
