Patient selection will be carried out by the respective co-investigators based on standard disease definitions. CIC/PBS is defined as urinary tract pain or discomfort and dysuria that is present of > 6 months and is not due to acute urinary tract infection, stones or other pathology. These patients will be identified and recruited by Dr. C. Lowell Parsons, Co-investigator for the study. rUTI is defined as greater than 2 urinary tract infections in 6 month or greater than 3 urinary tract infections in one year. These patient will be identified and recruited by Dr. Emily Lukacz, Co-investigator. Each study will enroll 20 individuals. The study design is an observational pilot study to determine feasibility and limited efficacy. Thus the primary outcomes will be the number of patients that enroll in the study relative to the number offered enrollment and the percentage of individuals completing the prescribed 40 treatment sessions. For the secondary outcome, limited efficacy, each patient's pre-treatment clinical status will be compared to their post treatment clinical status. Thus for the CIC/PBS study both the global response assessment (GRA) and the patient's overall rating of improvement of symptoms (PORIS) will be obtained and comparison between the pre and post treatment scores will be performed. For the UTI study, the time in days to subsequent acute urinary tract infection and total number of acute UTI's during one year following completion of HBOT will be recorded and compared to that individual's prior clinical history. The dosing algorithm to be used is based on the current standard of care for the treatment of radiation cystitis for which 2.4 ATA x 90 minutes is provided daily, 5 days per week. The total duration of treatment can range from 30-60 minutes depending upon the individual patients severity of illness and response to therapy. Patients are routinely reassessed after every 10-20 treatments. Therefore we are planning to provide 2.4 ATA x 90 minutes with 2 air breaks daily, x 5 days per week x 8 weeks total for both CIC/PBS and rUTI patient population. We will allow the 40 treatments to be administered over an 8-10 week time period to provide some degree of scheduling flexibility for patients.