his is a single-center, prospective, single-arm, interventional clinical study to evaluate the clinical efficacy, safety, and potential mechanisms of washed microbiota transplantation (WMT) in patients with recurrent urinary tract infections (rUTI). Recurrent UTI is defined as ≥2 episodes within 6 months or ≥3 episodes within 1 year. Traditional management relies heavily on antibiotics, which often lead to gut dysbiosis and increased infection risk. WMT may reconstruct intestinal microbiota, restore colonization resistance, and modulate immunity through the gut-bladder axis. Approximately 30 eligible patients will receive WMT via mid-gut or colonic transendoscopic enteral tubing (TET) for 2-3 times according to the Nanjing Consensus on Washed Microbiota Transplantation. Participants will be followed for 12 months.