Isolated constipation in the absence of alarm features is a frequent indication for colonoscopy, but the appropriateness and diagnostic value of the procedure in this setting remain controversial. We aimed to evaluate the diagnostic yield of colonoscopy in patients undergoing the examination for isolated constipation and to assess the impact of age on the detection of colonic lesions.

We conducted a retrospective single-centre study including adult patients who underwent colonoscopy for isolated constipation at Sahloul University Hospital. Isolated constipation was defined as constipation in the absence of rectal bleeding, melena, diarrhea or anemia as recorded in the colonoscopy report. Demographic data, colonoscopy completeness and endoscopic findings were collected. Colonoscopies were classified as abnormal if at least one significant organic lesion was present: colorectal polyp, colorectal tumor, diverticulosis, angiodysplasia or hemorrhoids; otherwise, they were considered normal. Patients were stratified by age (<50 vs ≥50 years). Comparisons were performed using χ² or Fisher’s exact test.

A total of 153 colonoscopies performed for isolated constipation were included. Among these patients, 112 (73.2%) were aged ≥50 years and 41 (26.8%) were <50 years. Colonoscopy was complete in 71.2% of cases. Overall, the examination was normal in 108/153 patients (70.6%) and abnormal in 45/153 (29.4%). The main lesions identified were:

Colorectal polyps: 22/153 (14.4%)

Colorectal tumors: 3/153 (2.0%)

Diverticulosis: 17/153 (11.1%)

Angiodysplasia: 3/153 (2.0%)

Hemorrhoids: 1/153 (0.7%).

Colorectal polyps and tumors combined were found in 25/153 patients (16.3%), and all colorectal tumors occurred in patients aged ≥50 years. The proportion of abnormal colonoscopies was 17.1% (7/41) in patients <50 years versus 33.9% (38/112) in those ≥50 years (p = 0.068), and colorectal polyps and/or tumors were observed in 9.8% (4/41) of patients <50 years and 18.7% (21/112) of those ≥50 years (p = 0.22). These differences did not reach statistical significance.

In this 153-patient series of colonoscopies for isolated constipation, over 70% of examinations were normal and colorectal polyps and cancer were uncommon, especially in patients <50 years, with all cancers occurring in those aged ≥50 years. As age-related differences were not statistically significant, colonoscopy for isolated constipation appears to have limited diagnostic value, and its use should be more selective and guided by individual risk and the presence of true alarm features.