CBI is indeed, continuous bladder irrigation.
Typically used in stubborn cases of gross hematuria in hospitalized patients (which can happen for a variety of reasons).
Most effective when used with the largest size 3-way foley catheter that can be inserted (typically, a 24 Fr, 3-way foley works well). If there is a clot suspected in the bladder, before starting CBI, hand-irrigating and aspirating sterile saline through the catheter (while plugging the 3rd input where the 3L bag of saline will be hooked up) can be very effective in breaking up and removing the clot. Once the clot has been removed by the hand irrigation/aspiration method (ie - no more clots and urine is returning clear), CBI can be initiated. CBI saline should NEVER be hooked up to an IV pump of any sort as there is a very real risk of bladder rupture should there be some sort of obstruction of the catheter drainage. The rate of CBI can be titrated (downward) to keep the urine clear and, eventually, is d/c'd.
Hope that helps.
Have a great day.