Gastrointestinal Seed Bezoars: A Systematic Review of Case Reports and Case Series

Seed bezoars are a distinct subcategory of phytobezoars, caused by indigestible vegetable or fruit seeds. The aim of our study was to present a comprehensive review on seed bezoars, focusing on epidemiology, symptomatology, diagnosis and treatment options. A systematic review of the English literature (1980-2018) was conducted, using PubMed, Embase and Google Scholar databases. Fifty-two studies fulfilled the inclusion criteria, with a total of 153 patients, the majority of whom (72%) came from countries around the Eastern Mediterranean and the Middle East. Patients complained primarily about constipation (63%), abdominal/rectal pain (19%) or intestinal obstruction (17%). Most seed bezoars were found in the rectum (78%) and the terminal ileum (16%). Risk factors were recognised in 12% of cases. Manual disimpaction under general anaesthesia was the procedure of choice in 69%, while surgery was required in 22% of cases. Seed bezoars appear to represent a different pathophysiological process compared to fibre bezoars. Seeds usually pass through the pylorus and ileocaecal valve, due to their small size, and accumulate gradually in the colon. Seed bezoars are usually found in the rectum of patients without predisposing factors, causing constipation and pain. History and digital rectal examination are the mainstay of diagnosis, with manual extraction under general anaesthesia being the procedure of choice.