Early Post-operative Removal of Urethral Catheter in Patients Undergoing Colorectal Surgery With Epidural Analgesia

Patients undergoing colon or rectal surgery will usually have a urinary catheter (silicone tube) placed in the bladder at the time of operating to monitor kidney function during surgery and in the post-surgery period. Such patients will also have an infusion into the spine, known as an epidural, after surgery to provide them with continuous pain relief. Urinary catheters should be removed as early as possible once they are no longer required to facilitate patients becoming mobile after surgery and to reduce the risk of patients developing a urinary tract infection. Traditionally these catheters are not removed until the patients epidural infusion is withdrawn, as in theory to do so would predispose the patient to developing acute retention of urine due to lack of sensation when the bladder is full. The investigators hypothesis is that urinary catheters placed via the urethra can be withdrawn 48 hours after colon/rectal surgery in patients receiving epidural pain relief without a significant increase in rates of urinary retention.