Factors affecting the quality of bowel preparation for colonoscopy in hard-to-prepare patients: Evidence from the literature

Constipation and colonoscopy

Constipation is a significant sociomedical problem, which can be caused by various reasons. In the diagnostic approach to patients with constipation, the following data are usually sufficient: History, complete physical examination (including rectal examination), and additional diagnostic tests. A colonoscopy is not a necessary diagnostic method for all patients with constipation. However, if patients have alarm symptoms/signs, that suggest an organic reason for constipation, a colonoscopy is necessary. The most important alarm symptoms/signs are age > 50 years, gastrointestinal bleeding, new-onset constipation, a palpable mass in the abdomen and rectum, weight loss, anemia, inflammatory bowel disease, and family history positive for colorectal cancer. Most endoscopists do not like to deal with patients with constipation. There are two reasons for this, namely the difficulty of endoscopy and the adequacy of preparation. Both are adversely affected by constipation. To improve the quality of colonoscopy in these patients, good examination techniques and often more extensive preparation are necessary. Good colonoscopy technique implies adequate psychological preparation of the patient, careful insertion of the endoscope with minimal insufflation, and early detection and resolution of loops. Bowel preparation for colonoscopy often requires prolonged preparation and sometimes the addition of other laxatives.

The Yield of Colonoscopy in the Evaluation of Constipation: An Age-Based Analysis of Outcome

Background: Chronic constipation, a prevalent gastrointestinal complaint, exhibits rising incidence and diverse clinical implications, especially among the aging population. This study aims to assess colonoscopy performance in chronic constipation across age groups, comprehensively evaluating diagnostic yield and comparing results with average-risk controls. Methods: A retrospective analysis was conducted on 50,578 colonoscopy procedures performed over 12 years, including 5478 constipated patients. An average-risk control group (n = 4100) was included. Data extracted from electronic medical records covered demographics, operational aspects, and colonoscopy findings. The primary outcome measures included the diagnosis rate of colorectal cancer (CRC), polyp detection rate (PDR), and inflammatory bowel disease (IBD) diagnoses in constipated patients versus controls, with age-based and multivariate analyses. Results: Constipated patients exhibiting lower rates of adequate bowel preparation (92.7% vs. 85.3%; p < 0.001) and a lower cecal intubation rate. No significant variances between CRC and PDR were observed between constipated and controls, except for a potential of a slightly elevated CRC risk in constipated patients older than 80 (2.50% vs. 0% in controls; p = 0.07). Multivariate analysis demonstrated, across all age groups, that constipation did not confer an increased risk for CRC or polyp detection. Younger constipated patients exhibited a higher rate of IBD diagnoses (1.7% vs. 0.1% in controls; p < 0.001). Conclusions: Constipation did not confer an increased risk for CRC or polyps, among any age groups, except for a potential signal of elevated CRC risk in patients older than 80; additionally, it was associated with higher rates of IBD in younger patients.

One-day versus three-day low-residue diet bowel preparation regimens before colonoscopy: a meta-analysis of randomized controlled trials

BACKGROUND AND AIM

Although studies have shown that the quality of bowel preparation with low-residue diet (LRD) is as effective as that of clear fluid diet (CLD), there is currently no consensus on how long an LRD should last. The aim of this study was to compare a 1-day versus 3-day LRD on bowel preparation before colonoscopy.

METHODS

A systematic review search was conducted in MEDLINE/PubMed, EMBASE, Web of Science, and Cochrane database from inception to April 2023. We identified randomized controlled trials (RCTs) that compared 1-day with 3-day LRD bowel cleansing regiments for patients undergoing colonoscopy. The rate of adequate bowel preparation, polyp detection rate, adenoma detection rate, tolerability, willingness to repeat preparation, and adverse events were estimated using odds ratios (OR) and 95% confidence interval (CI). We also performed meta-analysis to identify risk factors and predictors of inadequate preparation.

RESULTS

Four studies published between 2019 and 2023 with 1927 participants were included. The present meta-analysis suggested that 1-day LRD was comparable with 3-day LRD for adequate bowel preparation (OR 0.89; 95% CI, 0.65-1.21; P = 0.45; I2 = 0%; P = 0.52). The polyp detection rate (OR 0.94; 95% CI, 0.77-1.14; P = 0.52; I2 = 23%; P = 0.27) and adenoma detection rate (OR 0.87; 95% CI, 0.71-1.08; P = 0.21; I2 = 0%; P = 0.52) were similar between the groups. There were significantly higher odds of tolerability in patients consuming 1-day LRD compared with 3-day LRD (OR 1.64; 95% CI, 1.13-2.39; P < 0.01; I2 = 47%; P = 0.15). In addition, constipation was identified as the independent predictor of inadequate preparation (OR 1.98; 95% CI, 1.27-3.11; P < 0.01; I2 = 0%; P = 0.46).

CONCLUSION

The present study demonstrated that a 1-day LRD was as effective as a 3-day CLD in the quality of bowel preparation before colonoscopy and significantly improved tolerability of patients. In addition, constipation is an independent risk factor of poor bowel preparation, and the duration of LRD in patients with constipation still needs further clinical trials.

Prospective, randomized study comparing two different regimens of split-dose polyethylene glycol and their effect on endoscopic outcomes

BACKGROUND

Different split regimens of polyethylene glycol are routinely used and no guidelines are available to select an optimal protocol of ingestion. This study aims to compare the efficacy and side effect profile of two different regimens of polyethylene glycol bowel preparation solution: PEG (3 + 1) vs. PEG (2 + 2).

METHODS

240 patients above the age of 18 years were included in the study between June 1st and November 31st, 2023. Patients were randomly assigned either to Group A, consisting of 115 patients receiving a 3 L of PEG the night before the colonoscopy, and 1 L the same morning of the procedure. Or to group B, where 125 patients ingested 2 L the night before the procedure, and the remaining 2 L the same morning. The cleansing efficacy was evaluated by the attending endoscopist using the Boston Bowel Preparation Scale, through a score assigned for each segment of the colon (0-3). Side effects, tolerability, and willingness to retake the same preparation were listed by an independent investigator using a questionnaire administered before the procedure.

RESULTS

A higher percentage of patients had gastric fullness with the 3 + 1 vs. 2 + 2 preparation (58.3% vs. 31.2%; p <.001). A higher Boston bowel preparation score was seen in patients who took the 2 + 2 vs. 3 + 1 preparation (7.87 vs. 7.23). Using the 2 + 2 preparation was significantly associated with higher Boston bowel preparation scores vs. the 3 + 1 preparation (OR = 1.37, p =.001, 95% CI 1.14, 1.64). After adjustment over other variables (age, gender, comorbidities, previous abdominal surgeries, presence of adenoma, and time between last dose and colonoscopy), results remained the same (aOR = 1.34, p =.003, 95% CI 1.10, 1.62).

CONCLUSION

While both (2 + 2) and (3 + 1) regimens of polyethylene glycol are a good choice for a successful colonoscopy, we recommend the use of (2 + 2) regimen for its superior efficacy in bowel cleansing.

Predictors of inadequate bowel preparation in older patients undergoing colonoscopy: A systematic review and meta-analysis

BACKGROUND

Factors that predict the quality of bowel preparation in older adults are unclear, and current guidelines do not provide specific recommendations.

OBJECTIVE

This meta-analysis aimed to identify risk factors for inadequate bowel preparation in older patients.

METHODS

PubMed, Embase, Web of Science, China National Knowledge Infrastructure (CNKI), Wanfang, and VIP databases were searched from their inception to February 2023. Cohort and cross-sectional studies exploring the risk factors for inadequate bowel preparation were included in this systematic review. Odds ratio (OR) values from individual studies were pooled using fixed-effects and random-effects models. In addition, a sensitivity analysis and assessment of publication bias were performed.

RESULTS

This meta-analysis included six studies (n = 1553) on previous abdominal surgery, six studies (n = 1494) on constipation, seven studies (n = 1505) on diabetes, eight studies (n = 2093) on non-compliance with the diet regimen, seven studies (n = 1350) on incomplete intake of laxative, and nine studies (n = 2163) on inadequate exercise during preparation. The pooled analysis showed that history of abdominal surgery (OR = 2.72; 95 % confidence interval, CI: 2.07 to 3.56), constipation (OR = 3.56, 95 % CI: 2.41 to 5.25), diabetes (OR = 2.54, 95 % CI: 1.81 to 3.57), non-compliance with the diet regimen (OR = 2.51, 95 % CI: 1.96 to 3.21), incomplete intake of laxative (OR = 2.43, 95 % CI: 1.60 to 3.67), and inadequate exercise during preparation (OR = 3.13, 95 % CI: 2.39 to 4.11) were independent risk factors for inadequate bowel preparation in older patients undergoing colonoscopy.

CONCLUSIONS

Three comorbid factors and three behavioral factors were significantly associated with inadequate bowel preparation in older adults. This meta-analysis provides valuable information for developing predictive models of poor bowel preparation.

High volume, low volume, or pills, which way should we go? a review of bowel preparation for colonoscopy

PURPOSE OF REVIEW

Colorectal cancer (CRC) is the second leading cause of adult cancer-related deaths in the United States. Colonoscopy is the gold standard for CRC screening. Adequate bowel preparation prior to colonoscopy is essential for good visualization, which results in higher polyp detection rates and shorter procedural times. Achieving adequate preparation prior to colonoscopy is accomplished approximately 75% of the time. This review covers current recommendations and recent updates in bowel preparation for colonoscopy.

RECENT FINDINGS

Split-dose bowel preparation is recommended, but recent studies show that same day, low-volume preparations are noninferior. Low-volume polyethylene glycol with electrolytes + ascorbic acid can achieve high-quality bowel preparation and 1-day, low-residue diets prior to colonoscopy, particularly prepackaged low-residue diets, can lead to better outcomes. Utilizing visual aids and artificial intelligence in the form of smartphone applications and quality prediction systems can also lead to higher rates of bowel preparation adequacy.

SUMMARY

An individualized approach should be used to decide on the best preparation option for patients. Lower volume, same day preparations are available and lead to better patient tolerability and compliance, along with less stringent precolonoscopy diets. Smartphone applications and artificial intelligence will allow us to better educate and guide patients with regards to following preparation instructions.

Patient and healthcare professionals' perceptions of a combined blood and faecal immunochemical test for excluding colorectal cancer diagnosis in primary care

OBJECTIVES

To explore the perceptions of patients and healthcare professionals on Raman-faecal immunochemical test (FIT) as an alternative test for colorectal cancer exclusion in primary care.

DESIGN

Semi-structured interviews within a feasibility study.

SETTING

Patients presenting to primary care with colorectal symptoms and healthcare professionals working in primary and secondary care.

PARTICIPANTS

A total of 23 patients and 12 healthcare professionals.

METHODS

Patient participants were asked to complete a novel combined Raman-FIT test before being seen in secondary care. This study sought their opinions about the test. We also sought the views of healthcare professionals.

FINDINGS

Patients and healthcare professionals agreed that Raman-FIT was a suitable test to be given in primary care. It aligned with routine practice and was a simple test for most patients to complete.

CONCLUSIONS

Patients are willing and able to complete the Raman-FIT test in primary care. Raman-FIT may accelerate access to diagnosis with the potential to improve cancer outcomes.

PATIENT AND PUBLIC INVOLVEMENT

Lay members (J. H. and I. H.) with experience and knowledge of colorectal cancer and screening contributed to developing, undertaking, and disseminating all aspects of the research. They were supported to collaborate as equal members of the research team. They were involved in developing the study as coapplicants, using personal experience to ensure that the research and its methods were relevant to the patient and public needs. Both prepared participant information sheets, coanalysed data, and contributed to study reporting and dissemination through papers, conference presentations and a lay summary.

Focal Active Colitis: What Are Its Clinical Implications? A Narrative Review

Focal active colitis (FAC) is described as a histolopathological term indicating the isolated finding of focal neutrophil infiltration in the colonic crypts. Currently, there exist numerous debates regarding the clinical significance of diagnosing FAC, which may or may not have clinical relevance as it is frequently detected in colorectal biopsies without any other microscopic abnormalities. The objective of this narrative review is to provide an overview of the available evidence concerning the clinical implications of FAC, both in the adult population (among five studies available in the scientific literature) and in the pediatric context (based on two available studies).