Background <p>Sigmoid resection is the preferred treatment for diverticular colovesical fistula. To prevent postoperative intra-abdominal urine leakage, an indwelling urinary catheter (IUC) is placed, with cystography sometimes performed before IUC removal. Given the absence of well-defined postoperative guidelines, this study investigates diagnostic yield of cystography and IUC use.</p> Methods <p>We conducted a single-center retrospective cohort study of patients who underwent elective sigmoid resection for diverticulitis (2010–2023). Patients with colovesical fistula were identified. Data on patient characteristics, operative details, complications, postoperative IUC duration, and cystography use were analyzed.</p> Results <p>Sigmoid resection was performed in 204 patients, 55 (27.0%) of whom had a colovesical fistula. Simple bladder repair was performed in 18 (32.7%) patients, while four (7.3%) patients underwent complex repair. The remaining 33 (60%) patients did not undergo vesical closure. All 55 patients retained an IUC postoperatively, of whom 37 (67.3%) underwent cystography before IUC removal. Cystography was normal in 34 (91.9%) patients. In three patients, extravesical contrast was observed, resolving with extended IUC duration (7, 14, and 14&#xa0;days, respectively). In two of three cases, extravesical contrast occurred following complex bladder repair. Median IUC duration did not differ significantly between those with and without cystography (7 versus 6&#xa0;days, <i>p</i> = 0.104). However, median hospital stay was significantly longer in patients with fistula compared to patients without fistula (5 versus 4&#xa0;days, <i>p</i> = 0.040).</p> Conclusions <p>Postoperative cystography may not be necessary in patients with diverticular colovesical fistula without or after simple bladder repair. However, cystography should be considered if complex repair has been performed.</p> Trial registration number <p>20231001, 28 November 2023.</p>