InterStim Implants for Urinary or Bowel Incontinence

InterStim and Axonics Implants for Urinary or Bowel Incontinence

Incontinence can often be the result of a miscommunication between the brain and the bladder and/or bowels. Sacral neuromodulation therapy works to re-establish this very important communication channel. Incontinence Institute offers three implanted sacral neuromodulation devices: 

  1. InterStim II
  2. InterStim Micro
  3. Axonics

What is a sacral neuromodulation device?

Axonics, InterStim II and InterStim Micro are three different sacral neuromodulation (SNM) devices, similar in size and function to a pacemaker, implanted just beneath the skin of the pelvis above the buttocks. All three devices emit tiny electrical pulses, which target an area near the sacral nerves to adjust or fine-tune neural activity controlling the bladder and bowels. 

How does InterStim or Axonics therapy work?

InterStim and Axonics therapy work by stimulating the sacral nerves with tiny electrical pulses. In individuals experiencing urinary or fecal incontinence, the brain and the sacral nerves don’t communicate properly. Axonics and InterStim therapy attempt to better regulate the sacral nerves’ function, so the nerves can interpret signals from the brain and pass them on to the surrounding pelvic floor muscles. This restores normal bladder and bowel function.

Mild electrical pulses help the nerves to function normally, much in the same way that a pacemaker uses electrical impulses to keep the heart beating on a steady, predictable rhythm. The goal is to restore the normal functioning of the sacral nerves and reduce the improper signaling that can cause the sudden urge to go, going too often, or leaks.

As a result of the pulses from Axonics or InterStim devices, the symptoms of an overactive bladder or bowel incontinence are effectively eliminated. 

These devices are an option for patients who have not responded to more conservative treatments such as changes to diet, medication and physical therapy.

What’s the process for getting an InterStim or Axonics device?

Trial period and evaluation: Both InterStim and Axonics therapy begin with a two-week trial period employing a wearable, external version of the device to determine if the treatment is likely to be effective for a patient. 

Surgery: If the trial produces positive results, the device is implanted in a patient’s lower back near the sacral nerves. 

Post-surgery: After surgery, the doctor will program the device’s electrical signals based on the results from the trial period. 

InterStim and Axonics Therapy Trial Period

InterStim and Axonics Therapy both offer a trial device that simulates the actual, implanted device. Receiving the trial device is a 15-minute, minimally invasive outpatient procedure where the doctor places a lead connected to a small, externally worn device. The external device is worn underneath the patient’s clothing. 

Patients typically wear the trial device between 5-14 days to determine candidacy for a permanent device. During this time, patients log their symptoms to discuss with their doctors. They can continue about their normal activities and experience what it would be like to live with Axonics or InterStim therapy, how it feels when activated, and if the permanent device will be able to reduce or eliminate their symptoms.

How is an InterStim or Axonics device implanted?

The procedure to implant InterStim II, InterStim Micro or Axonics can be quickly and safely performed at an outpatient surgery center through a minimally invasive surgery. This can often be done under local anesthesia, though some doctors will prefer to use general anesthesia. The device is inserted in the lower back, above the buttocks. The procedure itself typically takes between 20-30 minutes to complete. 

Though insurance plans vary, Medicare and private insurance generally cover InterStim or Axonics treatment, but please consult with your doctor and insurance company.

How long does it take to recover from surgery?

Patients typically return to their normal activities within three weeks. Light activity is usually possible within a few days after surgery. 

What to Expect After the Device is Implanted

Most patients will notice a slight pulling or tingling sensation, according to Medtronic, which manufactures the InterStim devices. These impulses should not be painful — if they are, contact your doctor. A sudden movement can also cause the sensation of stimulation to change because the device has moved closer to or further from your sacral nerve. This doesn’t mean the level of stimulation has changed. Most patients also report that they no longer notice the electrical impulses after a few weeks. 

The goal is for InterStim or Axonics therapy to help patients return to normal activities without worrying about the risk of bladder or bowel leaks. A successful procedure should help patients be more confident of their ability to go through life and resume activities they were previously afraid to do because of bladder or fecal incontinence. Long walks, traveling or visits to a movie theater — things that can be difficult when patients are grappling with fecal or urinary incontinence — may now become a possibility for patients.

How do I program or manage an Axonics or InterStim device?

Patients have a hand-held programming remote that allows them to turn down or turn off the InterStim or Axonics device if needed. Doctors may also program the device to turn on and off at regular intervals if constant stimulation is not necessary. 

Will I be able to see the InterStim or Axonics device through my skin?

No, you will not be able to see InterStim II, InterStim Micro or Axonics devices through the skin once they’re implanted. 

Can the InterStim or Axonics device be removed?

Yes, the device can be removed. In the unlikely event that the procedure is not effective, it can easily be reversed.

What are the differences between Axonics, InterStim II and InterStim Micro?

InterStim II

  • About the size of a silver dollar, 44mm x 51 mm
  • Doesn’t require recharging
  • Needs to be replaced about every five years

InterStim Micro

  • Smallest SNM device available, 17 mm x 47 mm
  • Requires charging for 20 minutes, once a week
  • Needs to be replaced about every 15 years

Axonics Therapy

  • About the size of a quarter, 23 mm x 45 mm
  • Requires wireless charging for about an hour, once a month
  • Needs to be replaced about every 15 years

Sacral Neuromodulation for Urinary Incontinence

Bladder incontinence affects over 25 million Americans. There are many causes, including injury or trauma to the pelvic region or back, enlarged prostate or prostate cancer, pregnancy or childbirth, neurological disorders, estrogen loss following menopause, other health conditions like multiple sclerosis or suffering a stroke. 

Effectiveness of Axonics Therapy for Urinary Incontinence

93% of Axonics patients were satisfied with their therapy according to the ARTISAN-SNM study, which reviewed patients after one year of therapy: 

  • 75% overall reduction in urinary urge incontinence episodes
    • 77% of participants had a greater than 75% reduction in urinary urge episodes
    • 29% of responders were completely dry and had no incontinence episodes
  • 88% average reduction in large leak episodes
  • 74% of participants had a 100% reduction in large leaks

Study participants also recorded significant quality of life improvements in areas of sleep, concern, social interaction and coping.

Effectiveness of InterStim Devices for Urinary Incontinence

According to studies in the Journal of Urology and Medtronic’s own InterStim Therapy Clinical Summary, 82% of overactive bladder (OAB) patients achieved therapeutic success with an InterStim device at five years of treatment. 

  • 59% of urge incontinent patients achieved greater than 50% reduction in leaks/day
    • 71% of those urge incontinent patients who reported heavy leaks at baseline achieved greater than 50% reduction in leaks/day
  • 45% of patients had no incontinence episodes at five years of treatment
  • 56% of urgency-frequency patients achieved greater than 50% increase in volume voided and improved degree of urgency

Sacral Neuromodulation for Bowel Incontinence

According to a report from the University of Rochester, fecal incontinence affects as many as 18 million Americans. The most common causes are aging or injuries from giving birth. 

Effectiveness of Axonics Devices for Bowel Incontinence 

According to the ARTISAN‐SNM study: 

  • 58% reduction in fecal incontinence symptoms
  • 91% of participants reported being satisfied with Axonics therapy for their bowel symptoms

Effectiveness of InterStim Devices for Bowel Incontinence

In study results published in the medical journal “Annals of Surgery,” 120 patients and their doctors tracked the effectiveness of the therapy. 

  • About half of the patients experienced total recovery of bowel control and reported no incontinence problems for one year after the surgery 
  • 30% reported that their bowel leaks were reduced by more than 50%
  • InterStim therapy produced significant positive results for more than 8 out of 10 patients 

InterStim Therapy History

InterStim devices have been used to prevent urinary incontinence since 1997. In 2011, after extensive study, the Food and Drug Administration (FDA) also approved the use of the InterStim implant as a fecal incontinence treatment. Over 100,000 individuals have been treated with InterStim therapy.

Axonics Therapy History

Axonics is a relatively new device, having received FDA approval in September 2019. Since then, two new generations of devices have been approved, both of which have decreased the device recharging requirements. The third-generation Axonics device, available as of March 2021, also allows patients more ability to manage their devices using the remote control and manage symptom relief. 

Who is a good candidate for InterStim or Axonics therapy?

InterStim or Axonics can be an excellent choice for patients who haven’t experienced success with more conservative treatments, specifically men and women suffering from the following conditions:

  • Overactive bladder
  • Urinary or bowel urge incontinence
  • Urgency-frequency
  • Non-obstructive urinary retention
  • Chronic fecal incontinence

But it’s not ideal for all patients, including patients who:

  • Lack the motor skills needed to operate the InterStim or Axonics system
  • Are not good candidates for surgery
  • Suffer primarily from stress incontinence
  • Experience urinary retention due to benign prostatic hypertrophy (enlarged prostate)
  • Cancer or urethral stricture

These therapies may also not be a good choice for patients who are pregnant, are under the age of 16 or who have neurological issues as a result of a chronic condition such as diabetes or multiple sclerosis, since the safety and effectiveness of the treatment has not been established in these populations.

If you’ve tried conservative approaches for your urinary or fecal incontinence and your symptoms still interfere with your activities of daily living, InterStim or Axonics Therapy could be right for you. Contact our team of expert urinary and fecal incontinence doctors at our office in Nashville, TN.


To contact us or learn more, click here or call our discreet, dedicated Medical Concierge at 1.888.741.6403.

About The Incontinence Institute

At the Incontinence Institute, our team of healthcare providers understand the physical and mental trials that accompany living with urinary or bowel incontinence. Because of this, we are sensitive to your situation and treat all of our patients with the utmost respect and concern for discretion.


Individual incontinence conditions, treatment and recovery times may vary. Each patient's experience with incontinence procedures and / or surgery will differ. All surgical procedures involve some level of risk. If directed to pursue surgery by your physician, prompt action is advised, as waiting may reduce the efficacy of surgical treatment. The opinions expressed in patient testimonials are by patients only; they are not qualified medical professionals. These opinions should not be relied upon as, or in place of, the medical advice of a licensed doctor, etc.

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Incontinence Institute 2009 Mallory Lane, Suite 100 Franklin, Tennessee 37067

1.888.741.6403

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