What causes prostatitis? Different types of prostatitis have different causes. Risk factors for chronic pelvic pain syndrome (CPPS), the most common type, aren’t clear. Potential contributors to CPPS include: Autoimmune diseases. Pelvic floor muscle spasms. Stress. Potential causes of bacterial forms of prostatitis include: Bladder infections or bladder stones. Surgery or biopsy requiring use of a urinary catheter. Prostate stones. Urinary retention (not emptying the bladder completely). UTIs.