Ureterosigmoidostomy

A ureterosigmoidostomy is a surgical procedure where the ureters which carry urine from the kidneys, are diverted into the sigmoid colon. It is done as a treatment for bladder cancer, where the urinary bladder had to be removed. It was also used several decades ago as a correctional procedure for patients born with bladder exstrophy. In the case of some bladder exstrophy patients, occasional bowel incontinence (in this case, a mixture of urine and feces similar to diarrhea) at night is one uncontrollable consequence.

Another consequence of this procedure is an increased risk of kidney infections (nephritis) due to bacteria from faeces travelling back up the ureters (reflux).

As well as this, the urine entering the colon can cause diarrhea and salt imbalance due to the sodium and chloride in the urine. Urea levels in the blood are higher due to urea crossing the colon wall. In the large intestine, sodium is swapped for potassium, and chloride for bicarbonate, this causes an acidosis and hypokalaemia.

Patients with ureterosigmoidostomy have an increased chance of developing carcinoma of the colon after living with the modification for a number of years.

This operation is no longer popular in many countries, an ileal conduit (where the ureters lead into a loop of small intestine) being performed instead.