Colonoscopy in the young: An indication-based analysis of outcome.

Background: Data on colonoscopy's diagnostic yield in young adults with lower gastrointestinal symptoms are scarce. We evaluated this yield in young patients by performing an indication-based analysis of outcomes.

Methods: We reviewed diagnostic colonoscopies performed in young adults (age <50 years) over 10 years. We created two groups of young adults (18-39 years, n = 4941) and quadragenarians (40-49 years; n = 6605), included a control group of average-risk patients referred for screening colonoscopies during the same period (50-60 years, n = 1453). We evaluated clinical indications for colonoscopies among the young and performed an indication-based analysis of patients' outcomes.

Results: Chronic diarrhea and abdominal pain (42.4 and 36.2%), rectal bleeding (19.8 and 18.4%), and constipation were major indications for colonoscopy performance in quadragenarian and younger patients, respectively. Overall, diverticulosis (8.7 vs 1.3 and 3.9%; p < 0.000) and polyp detection rates (PDR) (19.6 vs 6.1 and 12.1; p < 0.000) were significantly higher in the control group, while inflammatory bowel disease (10.9 and 3.6% vs 0.1%; p < 0.000) was more prevalent in both young patients' groups. Indication-based analysis revealed that rectal bleeding was linked with increased PDR and significantly and independently associated with colorectal cancer (CRC) development (odds ratio = 10.160. p < 0.001 and 95% confidence interval = 6.201-16.647), even in the younger patients. In contrast, performing a colonoscopy for the evaluation of constipation was associated with the lowest yield.

Conclusion: We outlined the expected diagnostic yields of colonoscopy performed in young patients for multiple indications, showing that rectal bleeding was consistently associated with CRC and polyp detection.