Bladder inflammation: Inflammation of the urinary bladder. Also called cystitis. Can be due to infection from bacteria that ascend the urethra to the bladder or for unknown reasons, such as with interstitial cystitis.Symptoms include a frequent need to urinate, often accompanied by a burning sensation.As bladder inflammation progresses, blood may be observed in the urine and the patient may suffer cramps after urination. In young children, attempts to avoid the pain of cystitis can be a cause for daytime wetting (enuresis).ymptoms include a frequent need to urinate, often accompanied by a burning sensation. As bladder inflammation progresses, blood may be observed in the urine and the patient may suffer cramps after urination. In young children, attempts to avoid the pain of cystitis can be a cause for daytime wetting (enuresis).