Sacral Neuromodulation

What is sacral neuromodulation?

Sacral neuromodulation (SNM) is a treatment for bladder and bowel control problems (e.g. faecal incontinence). It’s sometimes called a bladder or bowel pacemaker.

It involves altering (or modulating) the activity of the sacral nerve, which supplies the bladder and bowel.

A nerve stimulator is implanted under the skin and then connected to the sacral nerve by a lead. The stimulator generates mild electrical pulses to the sacral nerve, which ‘normalises’ the messages between the brain and the bowel.

How is sacral neuromodulation performed?

Sacral neuromodulation is performed in two stages, the first is an evaluation/test phase and the next is the implant phase.

Evaluation phase

The evaluation phase allows your faecal incontinence specialist to assess whether or not your symptoms will be significantly reduced by SNM.

Before you take part in an evaluation, you will be asked to record your normal toilet habits and symptoms in a diary. This is used later to compare your symptoms with and without SNM.

A thin temporary wire is inserted near the sacral nerves in your lower back. The wire is then connected to a small device that delivers stimulation to the nerves. The device is worn on a belt for the duration of the evaluation. The procedure normally takes less than an hour and is generally a day procedure.

After the temporary wire is inserted you’ll go home and go about your daily life, continuing to record your toilet habits during this test in a new diary.

After two weeks of the home evaluation, your doctor will review and discuss the results with you. If your symptoms improved during the evaluation phase, you may go on to have a device implanted.

If your evaluation was unsuccessful, the temporary wire will be removed and your faecal incontinence specialist will discuss other options with you.

Implant phase

A small neurostimulator (similar to a pacemaker) is placed just beneath the skin in the upper buttock. A thin lead is also implanted in the lower back and connected to the device.

The neurostimulator battery lasts approximately 5 years. The device will need to be replaced when the battery runs out.

Sacral neuromodulation isn’t right for everyone. Your faecal incontinence specialist will help you work out if it’s a good option for you.