Efficacy and Tolerability of Guanylate Cyclase-C Agonists for Irritable Bowel Syndrome with Constipation and Chronic Idiopathic Constipation: A Systematic Review and Meta-Analysis.

OBJECTIVES: Linaclotide and plecanatide are guanylate cyclase-C (GCC) agonists for the treatment of chronic idiopathic constipation (CIC) and irritable bowel syndrome with constipation (IBS-C). Our objective is to evaluate the efficacy and tolerability of GCC agonists based on data from multiple randomized controlled trials (RCTs). METHODS: We searched PubMED, EMBASE, Cochrane databases, clinicaltrials.gov, major conference abstracts, Food and Drug Administration (FDA) websites, and United States Securities and Exchange Commission filings of drug sponsors to identify RCTs of CIC or IBS-C patients. We assessed efficacy based on FDA-approved composite responder endpoints, diarrhea as an adverse event, and study withdrawal owing to diarrhea for each therapy. Trial results were pooled using DerSimonian and Laird random effects model of meta-analysis and exact logistic regression when appropriate with 95% confidence intervals. Meta-regression was performed to compare outcomes between therapies adjusting for placebo event rate. RESULTS: Eight linaclotide trials (five CIC; three IBS-C) and seven plecanatide trials (four CIC; three IBS-C) evaluating 10,369 patients met inclusion criteria. FDA publications documented that different definitions for diarrhea were used in linaclotide vs. plecanatide trials. Both drugs were efficacious in treating CIC (linaclotide 72 µg (Odds ratio (OR)=3.11, 95% CI 1.81-5.34); linaclotide 145 µg (OR=3.25, 2.15-4.91); plecanatide 3 mg (OR=1.99, 1.57-2.51)) and IBS-C (linaclotide 290 µg (OR=2.43, 1.48-3.98); plecanatide 3 mg (OR=1.87, 1.47-2.38); plecanatide 6 mg (OR=1.92, 1.48-2.48)). Diarrhea occurred in excess of placebo in treating CIC (linaclotide 72 µg (OR=3.07, 1.97-4.77); linaclotide 145 µg (OR=3.70, 2.69-5.10); plecanatide 3 mg (OR=3.86, 1.83-8.12)) and IBS-C (linaclotide 290 µg (OR=8.02, 5.20-12.37); plecanatide 3 mg (OR=5.55, 1.62-19.00); plecanatide 6 mg (OR=4.13, 1.57-10.83)). Based on meta-regression, there were no statistically significant differences between therapies in odds ratios for efficacy, diarrhea, or diarrhea-related study withdrawals. CONCLUSIONS: Both linaclotide and plecanatide demonstrate similar efficacy and tolerability in treating IBS-C and CIC. No differences in odds of diarrhea were seen between linaclotide and plecanatide.

Low-Dose Linaclotide (72 µg) for Chronic Idiopathic Constipation: A 12-Week, Randomized, Double-Blind, Placebo-Controlled Trial.

OBJECTIVES: Linaclotide is a guanylate cyclase-C agonist approved in the United States, Canada, and Mexico at a once-daily 145-µg dose for the treatment of chronic idiopathic constipation (CIC); a once-daily 72-µg dose for CIC recently received FDA approval. The trial objective was to evaluate the efficacy and safety of a 72-µg linaclotide dose in CIC patients. METHODS: This double-blind, placebo-controlled trial randomized patients with CIC (Rome III criteria) to once-daily linaclotide 72 µg or 145 µg, or placebo for 12 weeks. The primary endpoint, 12-week complete spontaneous bowel movement (CSBM) overall responder, required patients to have ≥3 CSBMs and an increase of ≥1 CSBM per week from baseline in the same week for ≥9 of 12 weeks of the treatment period. Secondary endpoints included 12-week change from baseline in bowel (SBM and CSBM frequency, stool consistency, straining) and abdominal (bloating, discomfort) symptoms, monthly CSBM responders, and 12-week CSBM responders among patients who averaged >1 SBM/week at baseline. Sustained response (12-week CSBM overall responders who met weekly criteria for 3 of the 4 final weeks (weeks 9-12) of treatment) was evaluated as an additional endpoint. Adverse events (AEs) were monitored. RESULTS: The intent-to-treat population included 1,223 patients (mean age=46 years, female=77%, white=71%). The primary endpoint was met by 13.4% of linaclotide 72-µg patients vs. 4.7% of placebo patients (P<0.0001, odds ratio=3.0; statistically significant controlling for multiplicity). Sustained response was achieved by 12.4% of linaclotide 72-µg patients vs. 4.2% of placebo patients (nominal P<0.0001). Linaclotide 72-µg patients met 9-of-10 secondary endpoints vs. placebo (P<0.05; abdominal discomfort, P=0.1028). Patients treated with linaclotide 145 µg also improved CIC symptoms for the primary (12.4%) and sustained responder endpoint parameters (11.4%) and for all 10 of the secondary endpoint parameters including abdominal discomfort (P<0.05). Diarrhea, the most common AE, was mild in most instances and resulted in discontinuation of 0, 2.4%, and 3.2% of patients in the placebo, linaclotide 72-µg, and linaclotide 145-µg groups, respectively. CONCLUSIONS: Once-daily linaclotide 72 µg significantly improved CIC symptoms in both men and women with a low rate of discontinuation due to diarrhea over 12 weeks of treatment.

Who is Responsible for What Happens Before, During, and After Colonoscopy? Results of a National Survey of Primary Care Physicians.

BACKGROUND AND AIMS: Primary care providers (PCPs) play a critical role in colon cancer screening by initiating referrals to gastroenterologists for colonoscopy, but little is known about their role in pre-colonoscopy bowel preparation selection and pre-colonoscopy follow-up care. This study aimed to better understand coordination of care between PCPs and gastroenterologists as well as the current availability of "open-access" screening colonoscopy. METHODS: A multiple-choice survey was developed to assess PCPs' experiences with open-access colonoscopy, their involvement in the pre-colonoscopy process, and follow-up after colonoscopy. The survey was distributed electronically to a nationally representative sample of PCPs, via the American College of Physicians (ACP) Research Center's Internal Medicine Insider Research Panel. RESULTS: Of 442 PCPs invited to participate, 210 responded (response rate, 210/442, 48%), and 29 were ineligible (spent <25% of their time on clinical care or placed no referrals to colonoscopy), yielding 181 completed surveys. A total of 39% reported that open access was "rarely" or "never" available in their practice setting. The majority reported that pre-colonoscopy care was coordinated by gastroenterologists rather than PCPs. For example, 93% reported that gastroenterologists were responsible for bowel preparation selection in their practice setting. Post-colonoscopy, 54% of PCPs reported that they were responsible for ordering subsequent colonoscopies. CONCLUSIONS: PCPs frequently coordinate follow-up care postprocedure but play a relatively minor role in the pre-colonoscopy bowel preparation process. Open access availability for screening colonoscopy remains limited in this national sample of PCPs.

Repeat Treatment With Rifaximin Is Safe and Effective in Patients With Diarrhea-Predominant Irritable Bowel Syndrome.

BACKGROUND & AIMS: Few treatments have demonstrated efficacy and safety for diarrhea-predominant irritable bowel syndrome (IBS-D). A phase 3, randomized, double-blind, placebo-controlled trial was performed to evaluate the safety and efficacy of repeat treatment with the nonsystemic antibiotic rifaximin. METHODS: The trial included adults with IBS-D, mean abdominal pain and bloating scores of 3 or more, and loose stool, located at 270 centers in the United States and Europe from February 2012 through June 2014. Those responding to a 2-week course of open-label rifaximin 550 mg 3 times daily, who then relapsed during an observation phase (up to 18 weeks), were randomly assigned to groups given repeat treatments of rifaximin 550 mg or placebo 3 times daily for 2 weeks. The primary end point was percentage of responders after first repeat treatment, defined as a decrease in abdominal pain of ≥30% from baseline and a decrease in frequency of loose stools of ≥50% from baseline, for 2 or more weeks during a 4-week post-treatment period. RESULTS: Of 1074 patients (44.1%) who responded to open-label rifaximin, 382 (35.6%) did not relapse and 692 (64.4%) did; of these, 636 were randomly assigned to receive repeat treatment with rifaximin (n = 328) or placebo (n = 308). The percentage of responders was significantly greater with rifaximin than placebo (38.1% vs 31.5%; P = .03). The percentage of responders for abdominal pain (50.6% vs 42.2%; P = .018) was significantly greater with rifaximin than placebo, but not stool consistency (51.8% vs 50.0%; P = .42). Significant improvements were also noted for prevention of recurrence, durable response, and bowel movement urgency. Adverse event rates were low and similar between groups. CONCLUSIONS: In a phase 3 study of patients with relapsing symptoms of IBS-D, repeat rifaximin treatment was efficacious and well tolerated. ClinicalTrials.gov ID: NCT01543178.

Real-Time Characterization of Diminutive Colorectal Polyp Histology Using Narrow-Band Imaging: Implications for the Resect and Discard Strategy.

BACKGROUND & AIMS: Narrow-band imaging (NBI) allows real-time histologic classification of colorectal polyps. We investigated whether endoscopists without prior training in NBI can achieve the following thresholds recommended by the American Society for Gastrointestinal Endoscopy: for diminutive colorectal polyps characterized with high confidence, a ≥90% negative predictive value for adenomas in the rectosigmoid and a ≥90% agreement in surveillance intervals. METHODS: Twenty-six endoscopists from 2 tertiary care centers underwent standardized training in NBI interpretation. Endoscopists made real-time predictions of diminutive colorectal polyp histology and surveillance interval predictions based on NBI. Their performance was evaluated by comparing predicted with actual findings from histologic analysis. Multilevel logistic regression was used to assess predictors of performance. Cumulative summation analysis was used to characterize learning curves. RESULTS: The endoscopists performed 1451 colonoscopies and made 3012 diminutive polyp predictions (74.3% high confidence) using NBI. They made 898 immediate post-procedure surveillance interval predictions. An additional 505 surveillance intervals were determined with histology input. The overall negative predictive value for high-confidence characterizations in the rectosigmoid was 94.7% (95% confidence interval: 92.6%-96.8%) and the surveillance interval agreement was 91.2% (95% confidence interval: 89.7%-92.7%). Overall, 97.0% of surveillance interval predictions would have brought patients back on time or early. High-confidence characterization was the strongest predictor of accuracy (odds ratio = 3.42; 95% confidence interval: 2.72-4.29; P < .001). Performance improved over time, however, according to cumulative summation analysis, only 7 participants (26.9%) identified adenomas with sufficient sensitivity such that further auditing is not required. CONCLUSIONS: With standardized training, gastroenterologists without prior expertise in NBI were able to meet the negative predictive value and surveillance interval thresholds set forth by the American Society for Gastrointestinal Endoscopy. The majority of disagreement in surveillance interval brought patients back early. Performance improves with time, but most endoscopists will require ongoing auditing of performance. ClinicalTrials.gov ID NCT02441998.

Safety of Eluxadoline in Patients with Irritable Bowel Syndrome with Diarrhea.

OBJECTIVES: Eluxadoline is a mixed µ-opioid receptor (OR) and κ-OR agonist and δ-OR antagonist, approved for the treatment of irritable bowel syndrome with diarrhea (IBS-D). This analysis evaluated the safety and tolerability of eluxadoline 75 and 100 mg twice daily (BID) in one Phase 2 (IBS-2001) and two Phase 3 (IBS-3001 and IBS-3002) studies. METHODS: Adults with IBS-D (Rome III criteria) were randomized to placebo or eluxadoline (75 or 100 mg) BID for 12 (IBS-2001), 26 (IBS-3002), or 52 (IBS-3001) weeks. Safety data were pooled. Adverse events (AEs) were assessed, with special focus on opioid-related AEs, including suspected sphincter of Oddi spasm (SOS) events. RESULTS: 2,776 patients were included in the enrolled set; the safety set comprised 2,814 patients, based on actual treatments received. The most frequent AEs in the placebo and eluxadoline 75 and 100 mg groups were constipation (2.5, 7.4, and 8.1%, respectively) and nausea (5.0, 8.1, and 7.1%, respectively); discontinuation due to constipation was uncommon (0.3, 1.1, and 1.5%, respectively). Ten SOS events (10/1,839; 0.5%) occurred in eluxadoline-treated patients, manifesting as acute abdominal pain with elevated aminotransferases or lipase, or pancreatitis; all occurred in patients without a gallbladder. Eight of these events occurred with the higher dose of eluxadoline, within 1 week of initiation of therapy, and all resolved with eluxadoline discontinuation. There were five events independently adjudicated as pancreatitis not associated with SOS, three of which were associated with heavy alcohol use. CONCLUSIONS: Eluxadoline was well tolerated in Phase 2 and 3 trials, with constipation and nausea the most common AEs. Consistent with the known adverse effects of opioid agonists, clinically apparent SOS events were observed in eluxadoline-treated patients. All occurred in patients without a gallbladder and the majority were observed in patients on the higher dose of eluxadoline, suggesting a possible association.

Factors Associated with Surveillance Adenoma and Sessile Serrated Polyp Detection Rates.

BACKGROUND: Adenoma detection rate (ADR) and sessile serrated polyp detection rate (SSPDR) data in surveillance colonoscopy are limited. AIMS: Our aim was to determine surveillance ADR and SSPDR and identify associated predictors. METHODS: A retrospective review of subjects who underwent surveillance colonoscopy for adenoma and/or SSP at an academic center was performed. The following exclusion criteria were applied: prior colonoscopy ≤ 3 years, incomplete examination, or another indication for colonoscopy. Patient, endoscopist, and procedure characteristics were collected. Predictors were identified using multivariable logistic regression. RESULTS: Of 3807 colonoscopies, 2416 met inclusion criteria. Surveillance ADR was 49% and, SSPDR was 8%. Higher ADR was associated with: age per year (OR 1.03; 95% CI 1.02-1.04), male gender (OR 1.55; 95% CI 1.29-1.88), BMI per kg/m2 (OR 1.02; 95% CI 1.01-1.04), withdrawal time per minute (OR 1.09; 95% CI 1.07-1.10), and endoscopists' screening ADR (OR 1.01; 95% CI 1.00-1.03). Years since training (OR 0.99; 95% CI 0.98-0.99) was associated with lower ADR. Family history of CRC (OR 1.58; 95% CI 1.02-2.27) and endoscopists' screening ADR (OR 1.40; 95% CI 1.15-1.74) were associated with higher SSPDR. African-American race (OR 0.36; 95% CI 0.10-0.75) and diabetes (OR 0.41; 95% CI 0.21-0.76) were associated with lower SSPDR. CONCLUSIONS: For surveillance colonoscopy, nearly half of patients had an adenoma and one in twelve had an SSP. In addition to established factors, BMI, endoscopists' screening ADR, and years since training were associated with ADR, whereas African-American race and diabetes were inversely associated with SSPDR. Further studies are needed prior to integrating surveillance ADR and SSPDR into quality metrics.

Developing and Testing an Electronic Measure of Screening Colonoscopy Overuse in a Large Integrated Healthcare System.

BACKGROUND: Most existing performance measures focus on underuse of care, but there is growing interest in identifying and reducing overuse. OBJECTIVE: We aimed to develop a valid and reliable electronic performance measure of overuse of screening colonoscopy in the Veterans Affairs Health Care System (VA), and to quantify overuse in VA. DESIGN: This was a cross-sectional study with multiple cross-sections. SUBJECTS: U.S. Veterans who underwent screening colonoscopy between 2011 and 2013. MAIN MEASURES: Overuse of screening colonoscopy, using a validated electronic measure developed by an expert workgroup. KEY RESULTS: Compared to results obtained from manual record review, the electronic measure was highly specific (97 %) for overuse, but not sensitive (20 %). After exclusion of diagnostic and high-risk screening or surveillance procedures, the validated electronic measure identified 88,754 average-risk screening colonoscopies performed in VA during 2013. Of these, 20,530 (23 %) met the definition for probable (17 %) or possible (6 %) overuse. Substantial variation in colonoscopy overuse was noted between Veterans Integrated Care Networks (VISNs) and between facilities, with a nearly twofold difference between the maximum and minimum rates of overuse at the VISN level and a nearly eightfold difference at the facility level. Overuse at the VISN and facility level was relatively stable over time. CONCLUSIONS: Overuse of screening colonoscopy can be measured reliably and with high specificity using electronic data, and is common in a large integrated healthcare system. Overuse measures, such as those we have specified through a consensus workgroup process, could be combined with underuse measures to improve the appropriateness of colorectal cancer screening.

Comparing the effectiveness of competing tests for reducing colorectal cancer mortality: a network meta-analysis.

BACKGROUND: Comparative effectiveness data pertaining to competing colorectal cancer (CRC) screening tests do not exist but are necessary to guide clinical decision making and policy. OBJECTIVE: To perform a comparative synthesis of clinical outcomes studies evaluating the effects of competing tests on CRC-related mortality. DESIGN: Traditional and network meta-analyses. Two reviewers identified studies evaluating the effect of guaiac-based fecal occult blood testing (gFOBT), flexible sigmoidoscopy (FS), or colonoscopy on CRC-related mortality. INTERVENTIONS: gFOBT, FS, colonoscopy. MAIN OUTCOME MEASUREMENTS: Traditional meta-analysis was performed to produce pooled estimates of the effect of each modality on CRC mortality. Bayesian network meta-analysis (NMA) was performed to indirectly compare the effectiveness of screening modalities. Multiple sensitivity analyses were performed. RESULTS: Traditional meta-analysis revealed that, compared with no intervention, colonoscopy reduced CRC-related mortality by 57% (relative risk [RR] 0.43; 95% confidence interval [CI], 0.33-0.58), whereas FS reduced CRC-related mortality by 40% (RR 0.60; 95% CI, 0.45-0.78), and gFOBT reduced CRC-related mortality by 18% (RR 0.82; 95% CI, 0.76-0.88). NMA demonstrated nonsignificant trends favoring colonoscopy over FS (RR 0.71; 95% CI, 0.45-1.11) and FS over gFOBT (RR 0.74; 95% CI, 0.51-1.09) for reducing CRC-related deaths. NMA-based simulations, however, revealed that colonoscopy has a 94% probability of being the most effective test for reducing CRC mortality and a 99% probability of being most effective when the analysis is restricted to screening studies. LIMITATIONS: Randomized trials and observational studies were combined within the same analysis. CONCLUSION: Clinical outcomes studies demonstrate that gFOBT, FS, and colonoscopy are all effective in reducing CRC-related mortality. Network meta-analysis suggests that colonoscopy is the most effective test.

Protective role of gluteofemoral obesity in erosive oesophagitis and Barrett's oesophagus.

OBJECTIVE: Abdominal obesity has been associated with erosive oesophagitis (EO) and Barrett's oesophagus (BO). As gluteofemoral obesity protects against diabetes mellitus and cardiovascular disease, we hypothesised that gluteofemoral obesity would be inversely associated with EO and BO. DESIGN: We conducted a cross-sectional study on 822 male colorectal cancer screenees who were recruited to also undergo upper endoscopy. An additional 80 patients with BO clinically detected by upper endoscopy referred for clinical indications were recruited shortly after their diagnoses of BO. Logistic regression was used to estimate the effects of abdominal obesity (waist circumference), gluteofemoral obesity (hip circumference) and waist-to-hip ratio (WHR) on EO and BO (vs neither condition). RESULTS: There were 225 cases of either BO or EO and 675 controls. After adjustment for potential confounders, a positive association was observed between waist circumference and BO and/or EO, which became stronger with further adjustment for hip circumference. In contrast, hip circumference was inversely associated with BO and/or EO. Compared with the lowest quartile of WHR, the adjusted ORs were 1.32 (95% CI 0.747 to 2.33) for the 2nd quartile, 1.54 (95% CI 0.898 to 2.63) for the 3rd quartile, and 2.68 (95% CI 1.57 to 4.55) for the highest quartile. Similar results were obtained for BO and EO treated as separate outcomes. CONCLUSIONS: In a population of older, mostly overweight men, the distribution of obesity is associated with the presence of EO and BO. Abdominal obesity appears to increase the risk of these outcomes, whereas gluteofemoral obesity may be protective.

Association between Helicobacter pylori and Barrett's esophagus, erosive esophagitis, and gastroesophageal reflux symptoms.

BACKGROUND & AIMS: Infection with Helicobacter pylori, particularly the cytotoxin-associated gene A (cagA)+ strain, is believed to protect against Barrett's esophagus, but it is not clear if it protects against gastroesophageal reflux disease (GERD). We aimed to determine whether H pylori infection is associated with GERD symptoms, erosive esophagitis, and Barrett's esophagus within the same cohort. METHODS: We analyzed data from a case-control study of 533 men (ages, 50-79 y) who underwent colorectal cancer screening at 2 tertiary medical centers in Michigan between 2008 and 2011 and who also were recruited to undergo upper endoscopy. We assessed 80 additional men found to have Barrett's esophagus during clinically indicated upper-endoscopy examinations. Logistic regression was used to estimate the associations between serum antibodies against H pylori or cagA and GERD symptoms, esophagitis, and Barrett's esophagus, compared with randomly selected men undergoing colorectal cancer screens (n = 177). RESULTS: H pylori infection was associated inversely with Barrett's esophagus (odds ratio [OR], 0.53; 95% confidence interval [CI], 0.29-0.97), particularly the cagA+ strain (OR, 0.36; 95% CI, 0.14-0.90). There was a trend toward an inverse association with erosive esophagitis (H pylori OR, 0.63; 95% CI, 0.37-1.08; and cagA+ OR, 0.47; 95% CI, 0.21-1.03). However, GERD symptoms were not associated with H pylori infection (OR, 0.948; 95% CI, 0.548-1.64; and cagA+ OR, 0.967; 95% CI, 0.461-2.03). CONCLUSIONS: Based on a case-control study, infection with H pylori, particularly the cagA+ strain, is associated inversely with Barrett's esophagus. We observed a trend toward an inverse association with esophagitis, but not with GERD symptoms.

Associations of diabetes mellitus, insulin, leptin, and ghrelin with gastroesophageal reflux and Barrett's esophagus.

BACKGROUND & AIMS: Insulin and leptin have proliferative and anti-apoptotic effects. Ghrelin promotes gastric emptying and secretion of growth hormone and inhibits inflammation. We assessed whether diabetes mellitus and serum levels of insulin, leptin, and ghrelin are associated with gastroesophageal reflux disease (GERD) and Barrett's esophagus. METHODS: We conducted a case-control study in 822 men undergoing colorectal cancer screening who were recruited to also undergo upper endoscopy. We identified 70 with Barrett's esophagus; 80 additional men with Barrett's esophagus were recruited shortly after their clinical diagnoses. Serum levels of insulin, leptin, and ghrelin were assayed in all 104 fasting men with Barrett's esophagus without diabetes and 271 without diabetes or Barrett's esophagus. Logistic regression was used to estimate the effects of diabetes and levels of insulin, leptin, and ghrelin on GERD and Barrett's esophagus. RESULTS: Among men with GERD, diabetes was inversely associated with Barrett's esophagus (adjusted odds ratio [OR] = 0.383; 95% confidence interval [CI]: 0.179-0.821). Among nondiabetics, hyperinsulinemia was positively associated with Barrett's esophagus, but the association was attenuated by adjustment for leptin and ghrelin. Leptin was positively associated with Barrett's esophagus, adjusting for obesity, GERD, and levels of insulin and ghrelin (OR for 3(rd) vs 1(st) tertile = 3.25; 95% CI: 1.29-8.17); this association was stronger in men with GERD (P = .01 for OR heterogeneity). Ghrelin was positively associated with Barrett's esophagus (OR for an increment of 400 pg/mL = 1.39; 95% CI: 1.09-1.76), but inversely associated with GERD (OR for 3(rd) vs 1(st) tertile = 0.364; 95% CI: 0.195-0.680). CONCLUSIONS: Based on a case-control study, leptin was associated with Barrett's esophagus, particularly in men with GERD. Serum insulin level was associated with Barrett's esophagus, but might be mediated by leptin. Serum ghrelin was inversely associated with GERD, as hypothesized, but positively associated with Barrett's esophagus, contrary to our hypothesis. Additional studies are needed in men and women to replicate these findings.

The impact of bowel cleansing on follow-up recommendations in average-risk patients with a normal colonoscopy.

OBJECTIVES: Repeat colonoscopy in 10 years after a normal screening colonoscopy is recommended in an average-risk patient, and it has been proposed by American Gastroenterological Association (AGA), American College of Gastroenterology (ACG), and American Society for Gastrointestinal Endoscopy (ASGE) as a quality measure. However, there are little quantitative data about adherence to this recommendation or factors that may improve adherence. Our study quantifies adherence to this recommendation and the impact of suboptimal bowel preparation on adherence. METHODS: In this retrospective database study, endoscopy reports of average-risk individuals ≥50 years old with a normal screening colonoscopy were reviewed. Quality of colon cleansing was recorded using the Aronchick scale as excellent, good, fair, or poor. Main outcome measurements were quality of bowel preparation and recommendation for timing of repeat colonoscopy. Recommendations were considered consistent with guidelines if 10-year follow-up was documented after excellent, good, or fair prep or if ≤1-year follow-up was recommended after poor prep. RESULTS: Among 1,387 eligible patients, recommendations for follow-up colonoscopy inconsistent with guidelines were seen in 332 (23.9%) subjects. By bowel preparation quality, 15.3% of excellent/good, 75% of fair, and 31.6% of poor bowel preparations were assigned recommendations inconsistent with guidelines (P<0.001). Patients with fair (odds ratio=18.0; 95% confidence interval 12.0-28.0) were more likely to have recommendations inconsistent with guidelines compared with patients with excellent/good preps. CONCLUSIONS: Recommendations inconsistent with guidelines for 10-year intervals after a normal colonoscopy occurred in >20% of patients. Minimizing "fair" bowel preparations may be a helpful intervention to improve adherence to these recommendations.

Adherence to recommended intervals for surveillance colonoscopy in average-risk patients with 1 to 2 small (<1 cm) polyps on screening colonoscopy.

BACKGROUND: Among average-risk patients, repeat colonoscopy in 5 years is recommended after 1 to 2 small (<1 cm) adenomas are found on screening colonoscopy or in 10 years if hyperplastic polyps are found. However, sparse quantitative data are available about adherence to these recommendations or factors that may improve adherence. OBJECTIVE: To quantify adherence to recommended intervals and to identify factors associated with lack of adherence. DESIGN: Retrospective endoscopic database analysis. SETTING: Tertiary-care institution and Veterans Affairs Health System. PATIENTS: Average-risk individuals undergoing screening colonoscopy found to have 1 to 2 small polyps on screening colonoscopy. MAIN OUTCOME MEASUREMENTS: Frequency of recommending repeat colonoscopy in 5 years if 1 to 2 small adenomas are found and in 10 years if hyperplastic polyps are found. RESULTS: Of 922 outpatient screening colonoscopies with 1 to 2 small polyps found, 90.2% received appropriate recommendations for timing of repeat colonoscopy. Eighty-four percent of patients with 1 to 2 small adenomas and 94% of patients with 1 to 2 hyperplastic polyps received recommendations that were consistent with guidelines. Based on logistic regression analysis, patients aged >70 years (odds ratio [OR] 2.4, 95% confidence interval [CI], 1.0-5.7), fair bowel preparation (OR 12.7; 95% CI, 7.3-22.4), poor bowel preparation (OR 10.0; 95% CI, 4.3-23.6), and the presence of 2 small adenomas versus 1 small adenoma (OR 3.6; 95% CI, 2.2-6.0) were factors associated with "overuse" or recommendations inconsistent with guidelines. LIMITATIONS: Retrospective study design. CONCLUSION: More than 90% of endoscopists' recommendations for timing of surveillance colonoscopy in average-risk patients with 1 to 2 small polyps are consistent with guideline recommendations. Quality of preparation is strongly associated with deviation from guideline recommendations.

Patient compliance and suboptimal bowel preparation with split-dose bowel regimen in average-risk screening colonoscopy.

BACKGROUND: Although split-dose bowel regimen is recommended in colon cancer screening and surveillance guidelines, implementation in clinical practice has seemingly lagged because of concerns of patient compliance. OBJECTIVES: To assess patient compliance with the split-dose bowel regimen and assess patient- and preparation process-related factors associated with compliance and bowel preparation adequacy. DESIGN: Prospective survey cohort. SETTING: Tertiary care setting. PATIENTS: Average-risk patients undergoing colonoscopy for colorectal cancer screening between August 2011 and January 2013. MAIN OUTCOME MEASUREMENTS: Split-dose bowel regimen patient-reported compliance and bowel preparation adequacy with the Boston Bowel Preparation Scale score. RESULTS: Surveys and Boston Bowel Preparation Scale score data were completed in 462 participants; 15.4% were noncompliant with the split-dose bowel regimen, and suboptimal bowel preparation (score <5) was reported in 16% of all procedures. White (P = .009) and married (P = .01) subjects were least likely to be noncompliant, whereas Hispanic subjects and those who reported incomes of US$75,000 or less were most likely to be noncompliant (P = .004). Participants who were noncompliant with split-dosing were less likely to follow the other laxative instructions and more likely to have their colonoscopy appointment before 10:30 am. Compliance differed by bowel preparation type (P = .003, χ(2) test), with those who used MiraLAX showing the highest compliance, followed by polyethylene glycol electrolyte solution and other bowel preparations. Noncompliance with split-dose bowel preparation (odds ratio 6.7; 95% confidence interval, 3.2-14.2) was the strongest predictor of suboptimal bowel preparation. LIMITATIONS: Patient self-report, performed at tertiary care center. CONCLUSIONS: Overall, 1 in 7 patients do not comply with a split-dose bowel regimen. Ensuring compliance with the split-dose bowel regimen will reduce the risk of a suboptimal bowel preparation.

Efficacy of pharmacological therapies for the treatment of opioid-induced constipation: systematic review and meta-analysis.

OBJECTIVES: There has been no definitive synthesis of the evidence for any benefit of available pharmacological therapies in opioid-induced constipation (OIC). We conducted a systematic review and meta-analysis to address this deficit. METHODS: We searched MEDLINE, EMBASE, EMBASE Classic, and the Cochrane central register of controlled trials through to December 2012 to identify placebo-controlled trials of µ-opioid receptor antagonists, prucalopride, lubiprostone, and linaclotide in the treatment of adults with OIC. No minimum duration of therapy was required. Trials had to report a dichotomous assessment of overall response to therapy, and data were pooled using a random effects model. Effect of pharmacological therapies was reported as relative risk (RR) of failure to respond to therapy, with 95% confidence intervals (CIs). RESULTS: Fourteen eligible randomized controlled trials (RCTs) of µ-opioid receptor antagonists, containing 4,101 patients, were identified. These were superior to placebo for the treatment of OIC (RR of failure to respond to therapy=0.69; 95% CI 0.63-0.75). Methylnaltrexone (six RCTs, 1,610 patients, RR=0.66; 95% CI 0.54-0.84), naloxone (four trials, 798 patients, RR=0.64; 95% CI 0.56-0.72), and alvimopan (four RCTs, 1,693 patients, RR=0.71; 95% CI 0.65-0.78) were all superior to placebo. Total numbers of adverse events, diarrhea, and abdominal pain were significantly commoner when data from all RCTs were pooled. Reversal of analgesia did not occur more frequently with active therapy. Only one trial of prucalopride was identified, with a nonsignificant trend toward higher responder rates with active therapy. Two RCTs of lubiprostone were found, with significantly higher responder rates with lubiprostone in both, but reporting of data precluded meta-analysis. CONCLUSIONS: µ-Opioid receptor antagonists are safe and effective for the treatment of OIC. More data are required before the role of prucalopride or lubiprostone in the treatment of OIC are clear.