The KCL sensitivity test is a test performed in the office that can help to identify patients who have interstitial cystitis. The bladder in patients with interstitial cystitis is usually sensitive to solutions that contain pottasium, whereas normal bladders are usually not sensitive to pottasium.
A medical assistant will pass a small catheter through the urethra into the bladder and instill two different solutions. The patient is asked if the solutions produce an urge to urinate or bladder pain, and rank the amount of urgency and pain on a scale of 1-5. If patients have a lot of pain from one of the solutions the medical assistant will empty the bladder and instill a "rescue solution" that will decrease the pain. Patients with increased urgency or pain from the pottasium solution but not from water are more likely to have interstitial cystitis.
Patients who have interstitial cystitis can be more sensitive to catheterization than others. Some patients can have burning with urination or bladder pain for 1-2 days after the procedure. The risk of urinary infection after the procedure is 2%.