Clinical Research Directory

Inclusion Criteria: * Females 18 to 85 years old with at least a 1-year history of culture documented uncomplicated rUTI. * Diagnosis of rUTI, defined as ≥ 3 symptomatic UTIs in 12 months or ≥ 2 in 6 months. * Currently free from a UTI determined based on absence of symptoms as determined by the UTI symptom assessment questionnaire and negative urine culture (\<10\^3 colony forming units per ml of urine). * A negative upper and lower urinary tract evaluation, including pelvic examination for pelvic organ prolapse (less than or equal to stage 2), measurement of post-void residual (less than 50 ml), and imaging (which may include renal ultrasound and standing voiding cystourethrogram) to exclude kidney stone, hydronephrosis, reflux, or urethral diverticulum. * Office cystoscopy documenting stages 1 or 2 of chronic cystitis. * Likely to stay in the geographic region for the duration of the study. * ASA class II or less. Exclusion Criteria: * Patients on antibiotics at baseline (i.e., suppressive therapy or antibiotic therapy for non-urinary infections). * Patients on self-start therapy (i.e., taking antibiotics upon start of urinary symptoms concerning for UTI). * Patients on prophylactic antibiotics started in the last 3 months and unwilling to discontinue, or intention to start in the next 12 months. * Complicated UTIs, including neurogenic bladder condition (i.e., multiple sclerosis, Parkinson's disease, spinal cord injury), bladder augmentation, or urinary diversion. * Patients with urinary catheters (including indwelling Foley, intermittent catheterization, and suprapubic catheters). * Uncontrolled diabetes (HbA1c \>9). * Pregnancy * Allergy or resistance to Nitrofurantoin. * Chronic lung or liver condition precluding the use of Nitrofurantoin, including abnormal chest X ray or elevated liver function tests. * Chronic renal insufficiency (creatinine over 1.5 g/dl or GFR less than 40) precluding the use of Nitrofurantoin. * History of chronic diarrhea requiring regular therapy. * Patients with psychosis, dementia, swallowing disorders, or any other ability to take Nitrofurantoin reliably at home. * BMI over 40. * Use of Uromune or other vaccine approaches to reduce rUTI episodes * Participation in a research study involving an investigational product in the past 12 weeks. * Patients receiving phage therapy. * Current diagnosis of interstitial cystitis. * Patients with medical conditions requiring excessively large amounts of fluid intake.