The primary aim of this study is to assess the utility of prophylactic oral antibiotics at time of Bulkamid transurethral bulking to reduce the incidence of urinary tract infection (UTI) in the immediate postoperative period. The secondary aims of the study include assessing UTI rates and success rates if patients require temporary indwelling catheter versus intermittent self-catheterization (ISC).

Specific Aim 1: To determine if receiving prophylactic oral antibiotics at time of urethral bulking reduces the risk of post-operative urinary tract infection (UTI).

Patients will be randomized and blinded into two arms: oral antibiotic versus placebo. Patients will receive either the placebo pill or oral antibiotic in the pre-operative holding area prior to their procedure. Oral antibiotics will include trimethoprim/sulfamethoxazole (Bactrim, first line) or nitrofurantoin (Macrobid, second line), determined by patient allergies.

Specific Aim 2: To assess if factors such as patient discharge with ISC/indwelling foley or number of Bulkamid injection sites is correlated to improvement in Stress urinary incontinence (SUI) at 6 weeks postoperatively and at one year postoperatively.

Patients will complete a brief survey preoperative, at 6 weeks postoperatively after their procedure, and at 1 year postoperatively after their procedure. The survey will consist of prior validated urogynecologic surveys including the Pelvic Floor Disability Index/Urinary Distress Inventory (PFDI/UDI- 6) and the MESA questionnaires as well as an extended VAS scale to evaluate global improvement.

Specific Aim 3: To discern if any patient characteristics are associated with higher patient satisfaction following the procedure.

Inclusion Criteria

• Patients evaluated by a pelvic floor specialist (either urogynecologist or urologist) at The Ohio State University with plans to undergo urethral bulking with Bulkamid for stress urinary incontinence or mixed urinary incontinence (stress predominant).
• Negative testing for UTI in pre-operative work-up (including either negative urine culture or urine dip negative for infection).
• Office evaluation with evidence of SUI either with urodynamic studies (UDS) or positive cough stress test (CST).
• Post-void residual volume of 150 mL or less (measured by either catheterization or bladder scan)

Exclusion Criteria

• Contraindications to both oral antibiotics including antibiotic allergies or significant renal disease
• Patient undergoing additional pelvic organ prolapse procedures or other urologic procedures concomitantly
• Recurrent UTIs, defined as 3 or more UTIs within the past 12 months or 2 UTIs within the past 6 months
• Patients currently taking daily antibiotic prophylaxis for any reason
• Non-English speaking patients
• Pregnant patients
• Pelvic organ prolapse stage greater than 2
• Patients with immunosuppression due to underlying medical conditions
• Recent antibiotic treatment within one week of the procedure

Neither participants, providers, investigators or outcome assessors will know to which of these groups participants are assigned. In case of an emergency, however, the study doctor can get this information.