Reviving the poppy seed test for the diagnosis of colovesical fistula: A case report from a single rural center experience

Key Clinical MessageThe poppy seed test is a valuable, cost-effective, and sensitive initial diagnostic investigation to identify the presence of colovesical fistula, particularly for clinicians in remote or rural areas with lack of access to specialist radiologic, endoscopic, surgical, or urological support. The poppy seed test therefore may act as a bridge toward the commencement of appropriate referral pathways for the management of colovesical fistula.AbstractThe diagnosis of colovesical fistula is resource intensive, often requiring a combination of radiological investigation and endoscopy. The poppy seed test is a non-invasive and cost-effective alternative that has been demonstrated to identify presence of colovesical fistula with high sensitivity. There is however a noticeable paucity of recommendations for the poppy seed test in the diagnostic approach to colovesical fistula due to significant advancements in alternative radiologic and endoscopic technologies. Despite this, in resource-challenged areas with lack of specialist support, the poppy seed test is a cost-effective, accessible and safe test that can be performed to confirm the presence of colovesical fistula. We report a case of a 79-year-old man with a past history of colorectal cancer managed surgically with adjuvant chemoradiotherapy who develops noisy micturition, pneumaturia, and fecaluria 22 years after treatment. Given the suspicion of colovesical fistula, computed tomography imaging and cystoscopy were performed which was unable to demonstrate an overt fistula. The poppy seed test was utilized and demonstrated presence of poppy seeds in the urine, confirming the presence of a fistula. The patient was referred to a specialist surgical center for consideration of further management. The poppy seed test is a valuable initial diagnostic investigation for clinicians in remote or rural areas with lack of access to specialist radiologic, endoscopic, surgical, or urological support in confirming the presence of a colovesical fistula and initiating referral pathways for the management of this condition.