Will I wet myself under anesthesia? Here's what you should know

October 6, 2025 •

4 min read

While the worry is common, it is very rare to wet yourself under anesthesia, especially during general anesthesia. During longer surgical procedures, healthcare teams proactively manage bladder function with a urinary catheter to prevent this from occurring.

Quick Summary

Anesthesia affects bladder control by temporarily relaxing muscles and nerves that regulate urination, making the fear of an accident understandable. For long surgeries, a catheter is inserted to drain the bladder. For short procedures, the low risk is managed by emptying the bladder before surgery.

Key Points

Incontinence is Rare During Anesthesia: It is very rare to wet yourself under anesthesia, as anesthetic agents relax the bladder muscles and suppress the body's urination reflexes.
Catheters Prevent Accidents in Longer Surgeries: For procedures lasting more than a couple of hours or involving the pelvis, a urinary catheter is typically inserted after you are asleep to manage urine drainage.
Postoperative Urinary Retention is a Higher Risk: The most common bladder issue after surgery is difficulty urinating, or postoperative urinary retention (POUR), rather than incontinence.
Anesthesia Type Affects Bladder Control: Spinal and epidural anesthesia carry a higher risk of temporarily affecting the nerves controlling the bladder compared to general anesthesia, potentially causing delayed urinary function.
Several Factors Can Contribute to Postoperative Issues: Risk factors for POUR include the use of opioid pain medication, the location and length of surgery, and certain pre-existing conditions like an enlarged prostate or diabetes.
Medical Staff Actively Manage and Monitor Bladder Function: Your healthcare team will closely monitor your urinary function post-surgery and have established protocols for managing any issues that arise, including temporary catheterization if necessary.

Understanding how anesthesia affects the bladder

Anesthesia is designed to put the body into a controlled, unconscious state for surgery, and this includes affecting the nervous system that manages bladder function. Your urinary system is regulated by a complex network of nerves and muscles that coordinate the filling and emptying of the bladder. Anesthetic agents, particularly general anesthesia, temporarily suppress these nerve signals and reflexes at the spinal cord and brainstem level.

For most short-term outpatient procedures, you will be asked to empty your bladder right before the surgery begins. Because anesthetic agents relax the bladder muscles and suppress the urge to urinate, the risk of an involuntary accident during the procedure is very low. For longer surgeries, or those where significant intravenous fluid is administered, a more proactive measure is taken to prevent complications.

The role of urinary catheters

During many surgeries, especially those that are long or involve the abdomen or pelvis, a urinary catheter (often a Foley catheter) is routinely inserted after you are under anesthesia. This thin, flexible tube is inserted into the bladder through the urethra to ensure that urine can drain continuously into a collection bag. This practice serves several important purposes:

Prevents bladder distension: A full bladder can interfere with surgery, cause damage if overstretched, and lead to pain after waking up.
Monitors fluid balance: The volume of urine collected provides the medical team with vital information about your hydration levels and kidney function during surgery.
Reduces infection risk: By preventing bladder overfilling, catheters minimize the risk of urinary stasis, which can lead to urinary tract infections.

In many cases, the catheter is removed before you wake up in the recovery room, and patients may not even know it was used. For others, the catheter may remain in place for a longer recovery period.

The differences between anesthesia types

How likely you are to experience bladder control issues depends heavily on the type of anesthesia used. It is important to discuss these options with your anesthesiologist.


Feature	General Anesthesia	Spinal/Epidural Anesthesia
Mechanism of action	Induces a medically controlled coma, relaxing all smooth muscles, including the bladder.	Blocks nerve signals in the lower spinal cord, affecting the sensory and motor control of the lower body.
Risk of incontinence	Very low during the procedure due to muscle relaxation; more common as a temporary side effect after waking up.	Higher risk of causing temporary urinary retention or incontinence because it directly affects the nerves controlling the bladder.
Management	Often includes a catheter for longer surgeries to prevent bladder overfilling.	High likelihood of a catheter being placed to prevent postoperative urinary retention (POUR) until the anesthetic wears off.
Postoperative effects	Bladder function usually returns to normal as the anesthetic wears off, though temporary retention or urgency can occur.	Sensory and motor function returns over several hours, but nerve-blocking effects can delay the return of normal bladder control longer than with general anesthesia.

Factors contributing to postoperative issues

Even with proactive measures, some patients experience temporary bladder control issues after surgery, known as postoperative urinary retention (POUR) or, less commonly, incontinence. Several factors can contribute to this:

Opioid medications: Painkillers, particularly opioids, can dull the sensation of a full bladder and increase the risk of POUR.
Type and length of surgery: Surgeries involving the pelvis or spine can affect the nerves controlling the bladder, while longer procedures increase the risk of POUR.
Pre-existing conditions: Conditions like an enlarged prostate in men, diabetes, or a history of bladder control problems can increase the risk of postoperative issues.
Intravenous fluids: The amount of fluid given during surgery can increase urine output, putting more strain on the bladder.

What to expect during recovery

Your healthcare team will monitor your urinary function carefully after your procedure. For many, the first urination after surgery is a relief and signals a return to normal function. If you have difficulty, nurses are trained to help you get comfortable and may use techniques like encouraging you to walk around (if appropriate) or listening to running water. In cases of POUR, a temporary catheter may be reinserted until you regain full bladder control.

For most people, any bladder control issues resolve within a few days to weeks as the anesthetic and other medications leave the system and the body heals. For individuals with specific pre-existing conditions or those who have undergone complex pelvic surgery, the recovery may take longer.

Conclusion

The idea of losing bladder control under anesthesia is a common concern, but modern medical practices make it an extremely rare occurrence during surgery itself. For most patients, the primary concern is not incontinence but rather the temporary inability to urinate (urinary retention) after surgery, which is carefully managed by the medical team. Knowing the facts—that your bladder function is monitored and managed, especially during longer procedures with a catheter—can provide significant reassurance. Openly discussing your concerns and medical history with your healthcare provider is the best way to ensure a smooth and comfortable surgical experience and recovery.

For more information on bladder function and related conditions, resources from the National Institute of Diabetes and Digestive and Kidney Diseases can be very helpful.

Note: This article is for informational purposes only and is not a substitute for professional medical advice. Always consult with a healthcare professional regarding your specific medical conditions and treatment options.

Frequently Asked Questions

Accidents are extremely rare, and hospital staff are highly professional and accustomed to managing all aspects of patient care. Your comfort and dignity are a priority, and healthcare providers have seen and dealt with every possible scenario. The worry is far more common than the actual event.

For longer surgical procedures or those involving the pelvis or abdomen, a urinary catheter is often used to keep your bladder empty and allow the surgical team to monitor your fluid balance. For shorter procedures, a catheter is usually not necessary.

For most people, any temporary bladder control issues, like difficulty urinating, resolve within a few days to weeks after the anesthesia and other medications wear off. The duration can depend on the type of surgery, anesthesia used, and your individual health.

Postoperative urinary retention (POUR) is the inability to urinate after surgery despite having a full bladder. It can be caused by the lingering effects of anesthesia, pain medication (opioids), or nerve disruption from the surgical procedure.

If you have difficulty urinating after surgery, alert your care team. They may use a bladder scanner to check for a full bladder. If necessary, a temporary catheter may be used to drain the bladder until normal function returns.

Not necessarily. While general anesthesia relaxes bladder muscles, regional anesthesia like spinal or epidural blocks can more directly affect the nerves controlling urination, potentially delaying the return of bladder function for a longer period.

To prepare, you should empty your bladder right before the procedure. It is also important to discuss any pre-existing bladder issues or medications with your doctor beforehand. Following your doctor's instructions for post-surgery recovery, such as staying hydrated and ambulating when possible, can also help.