Bladder instillations are often a follow-up treatment used to help treat bladder conditions and control pain, as well as test for any abnormalities. This treatment is typically considered if other, more conservative measures to treat a condition were proven to be ineffective for the patient. First the bladder entrance is cleaned. Then a small catheter is placed in the bladder. Through this catheter, a variety of medications can be placed in the bladder to control pain or to test the bladder - as in a potassium sensitivity test. The catheter is then removed and you can go about your usual activity. The most common medication used during this procedure is dimethylsulfoxide (DMSO), a drug used to treat interstitial cystitis and bladder pain syndrome (IC/BPS). Some instillations will be a one-time treatment, while others may be a regularly scheduled treatment that can be self-administered or completed in an office.