Constipation is a common indication for colonoscopy, but the diagnostic yield of the procedure in patients with isolated constipation, in the absence of alarm features, remains debated. We aimed to compare the prevalence of colonic neoplastic and structural lesions in patients undergoing colonoscopy for isolated constipation versus other lower gastrointestinal indications.

We conducted a retrospective single-centre study including consecutive adult patients who underwent colonoscopy Sahloul hospital. Indications and findings were extracted from colonoscopy reports. Isolated constipation was defined as constipation without associated melena, rectorrhagia, diarrhea or anemia. The “other indications” group included patients with at least one of these features. Primary outcomes were the detection of colonic polyps and tumors. Diagnostic yields were compared using χ² tests.

A total of 120 colonoscopies were analyzed; approximately 73% of patients were aged 50 years or older. Constipation was the main indication, and isolated constipation accounted for about 65% of procedures, while the remaining 35% were performed for other indications (including anemia, melena, rectorrhagia and/or diarrhea).

The overall polyp detection rate was 23.2%, and colorectal tumors were found in 4.6% of examinations. In patients with isolated constipation, polyps were detected in 14.4% of procedures and tumors in 2.0%. In contrast, among patients with other indications, the polyp detection rate reached 35.7%, and tumor detection 9.5%. Both polyp and tumor yields were significantly lower in isolated constipation compared with other indications (p<0.001 and p=0.020, respectively). The rate of complete colonoscopy did not differ significantly between groups (around 71% vs 66%, p=0.44).

In this cohort, colonoscopy performed for isolated constipation had a substantially lower yield for polyps and colorectal tumors than colonoscopy performed for other lower gastrointestinal indications, although neoplastic lesions were not absent. These findings support a more selective use of colonoscopy in patients with isolated constipation and highlight the importance of alarm features such as anemia, bleeding and diarrhea in guiding the indication.