Continuous bladder irrigation (CBI) is a procedure that flushes your bladder with sterile fluid to prevent blood clots from forming after surgery. A steady stream of liquid flows into the bladder through a catheter while draining out at the same time, keeping the catheter clear and allowing urine to exit normally. It’s most commonly used in hospitals after prostate or bladder surgery, and it typically runs for three to five days.
How It Works
CBI uses a special catheter with three separate channels, often called a three-way catheter. One channel inflates a small balloon that holds the catheter in place inside the bladder. The second channel delivers sterile irrigation fluid from a hanging bag into the bladder. The third channel drains everything back out, a mix of irrigation fluid, urine, and any blood or tissue debris, into a collection bag below the bed.
The goal is simple: keep things moving. After surgery on the bladder or prostate, bleeding inside the bladder is expected. If blood pools and clots, those clots can block the catheter and trap urine. That backup, called bladder tamponade, causes pain, swelling, and potentially serious complications. By continuously flushing the bladder, CBI washes clots out before they have a chance to form and block drainage.
Why You Might Need It
The two most common reasons for CBI are transurethral resection of the prostate (TURP) and transurethral resection of a bladder tumor (TURBT). Both procedures involve cutting tissue inside the bladder or prostate through the urethra, which leaves raw surfaces that bleed as they heal. CBI is started in the operating room or recovery area and continues at the bedside.
Other situations that call for CBI include severe blood in the urine from causes like trauma, radiation injury to the bladder, or certain cancers. In these cases, the purpose is the same: prevent clot formation and keep the catheter draining freely.
What the Fluid Looks Like and Why It Matters
The color of the fluid draining out of your catheter is the main way your care team monitors your recovery. Right after surgery, drainage is often dark red or even cherry-colored. Over the following hours and days, it should gradually lighten to pink, then to a pale straw color resembling diluted urine. Your nurse will check this frequently.
The flow rate of the irrigation is adjusted based on what the drainage looks like. If the fluid coming out is dark or contains visible clots, the flow is increased to flush the bladder more aggressively. As drainage clears, the flow is slowed down. This gradual reduction continues until the drainage runs consistently clear, at which point the irrigation can be stopped and, eventually, the catheter removed.
What It Feels Like
You’ll feel the catheter itself, which can cause a persistent urge to urinate or a sense of pressure in your lower abdomen. The irrigation fluid is at room temperature, and some people notice a cool sensation in the bladder as it flows in. The most common discomfort is bladder spasms, which feel like sudden, intense cramping in the lower belly, sometimes with a strong urge to push. Studies report that between 11% and 29% of patients experience bladder spasms during CBI after prostate surgery. These spasms happen because the bladder muscle contracts in response to the catheter and the constant flow of fluid. They can be managed with medication, and they stop once the irrigation and catheter are removed.
You won’t need to get up to use the bathroom while CBI is running. Everything drains through the catheter into the collection bag. You will, however, be connected to an IV pole with the irrigation bags, which limits your mobility somewhat. Nurses typically change the bags as they empty, sometimes going through several liters in a day.
How Fluid Balance Is Tracked
Because large volumes of fluid are flowing in and out of your body, your care team carefully tracks the numbers to make sure your kidneys are still producing urine normally. The calculation is straightforward: they subtract the total volume of irrigation fluid that went in from the total volume of fluid that drained out. The difference is your actual urine output.
For example, if 2,000 mL of irrigation fluid was infused and 2,400 mL drained out, your true urine output was 400 mL. If the drainage volume is ever less than what was infused, that’s a red flag. It could mean the catheter is blocked, fluid is being retained in the bladder, or fluid is being absorbed into the body. Your nurse will investigate immediately.
What the Irrigation Fluid Contains
For CBI after surgery, the irrigation fluid is typically normal saline, a salt solution that matches the concentration of your blood. This is important because if a large amount of fluid gets absorbed through the surgical site into the bloodstream, a solution that matches your body’s salt balance is far safer than plain water. Distilled water, which is sometimes used in other settings, can dilute the sodium in your blood and cause cellular swelling. Normal saline largely avoids this risk.
One rare but serious complication historically associated with prostate surgery is called TURP syndrome. It happens when the body absorbs a large volume of irrigation fluid (2,000 mL or more), which dilutes sodium levels in the blood. Symptoms range from headache and confusion to seizures and, in extreme cases, coma. This complication is more associated with older surgical techniques that used non-saline solutions. Modern CBI with normal saline and newer surgical methods have made it much less common, but it’s one of the reasons your care team monitors you closely.
Common Problems and How They’re Handled
The most frequent issue during CBI is a blocked catheter. Blood clots, tissue fragments, or mucus can clog the drainage channel, causing fluid to back up in the bladder. You might notice that the drainage bag stops filling, your abdomen feels increasingly full or painful, or fluid starts leaking around the catheter. If this happens, there are several steps your nurse will take:
- Checking the tubing. Kinks in the line, clothing pressing on the tube, or lying on the drainage tubing can all stop flow without an actual blockage.
- Repositioning the catheter. Gently twisting the catheter 90 to 180 degrees at the skin can free it if the drainage holes are pressed against the bladder wall.
- Milking the tubing. Pressing and releasing along the length of the external tubing can dislodge small clots stuck inside.
- Manual irrigation. If gentle methods don’t work, a syringe is used to flush saline directly through the catheter under light pressure to break up and extract clots.
- Catheter replacement. In cases where the blockage can’t be cleared, the catheter is removed and a new one is inserted.
The drainage bag should always hang below the level of your bladder and should not be allowed to fill beyond three-quarters capacity. If you’re in the hospital with CBI and notice the bag looks very full or the fluid has stopped moving, let your nurse know right away.
How Long CBI Lasts
Most patients are on CBI for three to five days after prostate or bladder surgery, though this varies based on how quickly the bleeding resolves. The irrigation is gradually slowed as drainage clears, and once the fluid runs consistently light yellow or clear for several hours, the irrigation is discontinued. The catheter itself may stay in for an additional day or two after irrigation stops, depending on the procedure and how healing is progressing.