Even Alzheimer s can cause a neurological disorder leading to inability to urinate. The issue could be easily solved by a prostate biopsy if the rectal exam is suspicious. If the cancer is diagnosed the treatment could be as simple as hormonal injection. Even a prostate biopsy could precipitate infection similar to one he had that required hospitalization and requires antibiotic coverage. Repeating the PSA would not help as it will be high merely because of the presence of the catheter.
Urethral discharge is often a problem with long term catheters.
Generally, urinary problems, including incontinence, with Alzheimer s can be difficult to manage. Discussing all issues with the Urologist should help. This information is provided for general medical information purposes only. Please consult your physician for diagnostic and treatment options pertaining to your specific medical condition. The Henry Ford Hospital Department of Urology has experience in the evaluation and treatment of problems such as you describe.