Abstract
The composition of the distal ileum microbiota and the impact of fecal exposure during intracorporeal urinary diversion (ICUD) on gastrointestinal (GI) complications remain unclear. This study included 146 patients with bladder cancer who underwent ICUD without bowel preparation and received only a single day of antibiotic prophylaxis. Fecal samples were collected directly from the distal ileum during surgery, and ascitic fluid was obtained postoperatively from abdominal drains. Among the patients, 129 (88.3%) had minimal microbial growth in ileal feces, while 17 (11.7%) showed significant colonization. The most commonly identified organisms were Streptococcus, Enterococcus, Enterobacter, Klebsiella, and Candida. The incidence of GI complications was significantly higher in patients with positive ileal fecal cultures compared to those with no detectable growth (39.4% vs. 7.7%, P < 0.001), and even more pronounced in patients with positive ascitic cultures (72.5% vs. 11.3%, P < 0.001). Multivariate analysis identified positive ascitic cultures as an independent predictor of GI complications. Additionally, frailty was significantly associated with the presence of microbial growth in ascitic fluid. These findings suggest that, although the distal ileal microbiota is largely suppressed under short-term antibiotic prophylaxis, the presence of intra-abdominal bacteria or fungi is strongly linked to postoperative GI complications, including ileus. Frailty may contribute to microbial dysbiosis and the persistence of intra-abdominal pathogens, particularly Enterococcus and Enterobacter species.