Background Colonic mural thickening (MT) is often reported on standard CT examinations of the abdomen and pelvis. It often presents a dilemma for the clinician on whether any further evaluation is needed, especially in the absence of any set guidelines.

Objective To evaluate the significance of colonic MT and to assess its correlation with colonoscopy.

Methods The search strategy was initially developed in Medline and adapted for use in Embase, Medline, NHS Evidence and TRIP. Studies were included if they had reported colonic MT and subsequent colonoscopy in adults.

Results A total of 9 cohort studies examining 1252 patients were selected having undergone both CT and colonoscopy. Of the 1252 patients with MT, 950 had an abnormal colonoscopy. In the presence of MT, the pooled positive predictive value (PPV) of having any abnormal findings at colonoscopy was 0.73 (95% CI 0.60 to 0.84). The pooled PPV for colorectal cancer, in the presence of MT reporting suspicion of cancer, was 0.63 (95% CI 0.49 to 0.75), and MT suggestive of inflammation confirmed at colonoscopy was 0.97.

Conclusion The probability of having an abnormal colonoscopy in the presence of MT identified on CT is high, especially for inflammation. Asymptomatic cancers may also be detected; hence, further endoscopic confirmation is reasonable when a finding of MT is demonstrated on CT examinations. Small sample sizes of the available studies and lack of data on the description of MT detected are the main limiting factors in this review.

Trial registration number CRD42016039378.