Luminary Learning Gastrointestinal Disorder- Issue 1

Current Guidelines for Colonoscopy •  35 to understand and participate in the process of screening rather than being traumatized. The risk of this delay is negligible as a proctocolectomy is almost never needed before the age of 14. The purpose of flexible sigmoidoscopy or colonoscopy in FAP is less to prevent CRC but to get a rela- tive growth profile and establish the right timing for the inevitable surgery. In contrast, Lynch syndrome (HNPCC) has a more variable phenotype. Patients with a clini- cal or genetic confirmation of a carrier status are recommended to begin colonoscopy screening at age 20–25 years or 10 years before the youngest family member with CRC or advanced polyps and to subsequently continue every 1 or 2 years. Quality Assessment Parameters The efficacy of colonoscopy as a screening tool has been linked to a number of quality parameters that involve: (a) the endoscopist, (b) the patient and the bowel preparation, and (c) potentially some technological aspects (see Table 4) [13, 14]. The clinically most relevant though unpractical parameter would be the detection rate of interval cancers. Hence, the most important surrogate parameter appears to be the overall adenoma detection rate. Other similar parameters such as polyp detection rate (which includes hyperplastic polyps), the overall cecal intubation rate with photo documentation, and the average withdrawal time (typically greater than 6 min) have been used as quality benchmarks even though strong supportive evidence is lacking. Unquestionably, visibility is highly dependent on the completeness of the bowel cleansing. An adequate bowel preparation is critical for the accuracy and cost-effectiveness of colorectal cancer screening while inadequate cleansing should trigger an earlier reexamination [15]. Follow-up Surveillance and Repeat Intervals After a previous polypectomy or colon resection for CRC, the aim of repeat colonoscopies is to detect and remove adenomata that were potentially missed on the initial exam as well as metachronous new adenomata with advanced pathologic features [16]. Defining the exact length of recommended interval depends on the number of factors to not only include the previously mentioned overall risk categories but also the individual findings (Table 5). In particular, the number of detected and removed adenomatous or serrated polyps, the completeness of the previ- ous removal, the size of lesions, and the presence or absences of unfavorable features (e.g., high- grade dysplasia) have to be taken into account. Furthermore, the time interval may need to be shortened depending on the quality of the previous examination, e.g., if it was complete or the bowel cleansing and visibility were inadequate. If there were only a limited number of small adenomata (tubular adenoma), a 5- to even 10-year interval is sufficient. A shorter interval of 3 years would be recommended if there were more advanced or multiple polyps (≥ 3), including sessile serrated adenomata proximal to sigmoid colon. In patients who were found to have numerous adenomata (including serrated adenoma), a malignant adenomatous polyp with high-grade dysplasia or focal adenocarcinoma (cancerous polyp), large sessile polyps including sessile serrated adenomata, incomplete removal of polyps,