Introduction Diverticulitis, the common clinical complication of diverticulosis, may affect 10%–25% of patients with colonic diverticula. The diagnosis of diverticulitis may be made on clinical grounds. However, it is usual practice to perform a CT scan to confirm the diagnosis and assess for complications (eg, abscess, fistula, obstruction). CT criteria suggestive of diverticulitis include: presence of diverticula with pericolic infiltration of fatty tissue, thickening of the colonic wall, and abscess formation. The sensitivity of CT scan in diagnosing of diverticulitis is up to 97%. Once an episode of diverticulitis has been treated, we have observed patients to be followed up by undergoing routine colonoscopy (CSy). We hypothesised that the value of CSy in patients with a confirmed CT diagnosis of diverticulitis is negligible.

Methods A duel centre (2 North London hospitals), retrospective analysis of all patients with an ICD 10 coding on their in-patient discharge summary letters of diverticular disease (DD) over the past year was employed. Patient notes were scrutinised and correlated to endoscopic records. The dates of both CT scan and CSy were recorded. Completion rates of the endoscopies and findings in addition to diverticular disease was noted.

Results 137 patients over a 4-month period had DD recorded within the discharge summary. 47 patients with presumed diagnosis of diverticulitis had a CT scan prior to endoscopy (35 CSy and/12 Flexible sigmoidoscopy). Of the 47, DD was evident on the CT scan in 34. Endoscopy subsequently confirmed DD in 32/34 of these cases (95%), with four procedures ending in failure. No other pathological features were found in 30/34 cases. Within the cohort of 32 patients in which endoscopy confirmed CT, three had colonic polyps. Of the 13 cases (of 47) in which DD was not reported on the prior CT scan, subsequent endoscopy confirmed DD in 11/13, with one procedure ending in failure. Of these 11 cases, one had a colonic polyp. In the two cases where endoscopy did not reveal DD, a diagnosis of colitis was recorded.

Conclusion In this study, performing a CSy in patients previously diagnosed with diverticulitis confirmed on CT scan add no further information. CSy is only useful in the setting of clinical diverticulitis if the diagnosis is not supported by CT scan. In patients with diverticulitis other diagnosis such as polyps were detected in only 4 of 47 patients (8%), not a unsurprising finding as one would expect to find polyps at routine CSy in upto 25%. From this study, we would not support performing a CSy in patients with clinical diverticulitis confirmed on CT scan and avoiding CSy could save 100 colonoscopies per annum in a hospital like ours freeing up space to perform other procedures with more appropriate indications.

Competing interests None declared.