Yield of adenomas and colorectal cancers within 5 years of a negative colonoscopy: are the guidelines guiding?

Optimal Colonoscopic Surveillance Interval After Normal Baseline Screening Colonoscopy

The optimal colonoscopic surveillance interval in the Chinese population is unclear. The present study aimed to assess the optimal colonoscopic surveillance interval after normal baseline screening colonoscopy to avoid overuse or underuse of colonoscopy. This retrospective study included individuals with normal baseline colonoscopy who had undergone at least 2 follow-up colonoscopy examinations at the Digestive Endoscopy Center of our hospital between 2000 and 2013. The risk factors for adenoma and the optimal colonoscopic surveillance interval were assessed. A total of 1,005 individuals (419 men; mean age, 49.34 ± 13.29 years) were included in the study. Of these, 169 individuals had adenomas at colonoscopic surveillance (mean, 1.32 ± 0.79 procedures). The mean adenoma diameter was 0.54 ± 0.38 cm, and the mean number of adenomas was 1.76 ± 1.29. The mean adenoma surveillance interval was 4.76 ± 2.89 years. The risk factors for adenoma identification were age more than 50 years and male gender. The optimal colonoscopic surveillance interval was 4.76 years according to an adenoma detection rate of 5%. The optimal colonoscopic surveillance interval is around 5 years for individuals with normal baseline colonoscopy. Age more than 50 years and male gender are risk factors for adenoma identification.

Hydrogen Breath Testing Predicts Bowel Preparation Quality Prior to Colonoscopy: A Systematic Review

Background

This systematic review aims to assess the accuracy of hydrogen breath testing as a predictor of bowel preparation.

Methods

Studies were identified from MEDLINE, Embase, Web of Science, Cochrane Library and clinicaltrials.gov. Two investigators evaluated abstracts for inclusion criteria - report of correlation between hydrogen breath levels and bowel preparation quality, prospective design and non-emergent colonoscopy in adults. Included studies underwent duplicate data extraction using a standardized approach. The Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool assessed quality of the studies.

Results

One hundred fifty-nine publications were identified, and six unique studies met inclusion criteria. The number of patients analyzed ranged from 61 to 127. Three studies were performed in the USA, one in Japan and two in Italy. Three studies used a prebiotic in addition to a purgative, with the intention of enhancing the discriminating ability of hydrogen breath levels. Three studies assessed baseline hydrogen levels. In five of the six studies, hydrogen breath levels were predictive of inadequate bowel preparation. Suggested absolute hydrogen levels to distinguish adequate from inadequate bowel preparation ranged from 3 to 10 parts per million. Depending on the cutoff value, sensitivity ranged from 71% to 100% and specificity from 87% to 100%. There was significant heterogeneity among studies in breath testing protocol and breath analyzer used. Full-text studies had low risk of bias in most assessed domains.

Conclusion

Hydrogen breath levels predict bowel preparation adequacy but existing studies have significant limitations. Further studies should use standardized methods and consider the real-world practicality of self-administered home breath testing.