Benefits and Risks –
InterStim® Therapy

If you’ve tried other treatments for your bladder or bowel problems without success, or you’ve experienced intolerable side effects from medications, sacral neuromodulation with InterStim Therapy may provide you relief from your difficulties with overactive bladder, urinary retention, fecal incontinence or constipation.


Sacral neuromodulation (also called sacral nerve stimulation) is reversible and can be discontinued at any time. People who have had InterStim Therapy for faecal incontinence have reported:

  • Improved quality of life1–5
  • Complete freedom from incontinence episodes or a dramatic reduction1–5
  • Freedom to live without worry of leaks.5

People who have had InterStim Therapy for constipation have reported:

  • Major improvements in the number of bowel movements per week6
  • Freedom from abdominal pain6
  • Improved quality of life.7

People who have had InterStim Therapy for overactive bladder have reported:

  • Major improvements in the number of incontinence episodes each week, with a large number of people being completely free of incontinence8
  • A major reduction in the number of times they have to visit the toilet each day9
  • Improved quality of life.10

People who have had InterStim Therapy for urinary retention have reported:

  • An increase in the amount of urine produced on each visit to the toilet11
  • Freedom from catheterization11
  • Improved quality of life.12

You and your doctor can test InterStim Therapy without making a big commitment.

The evaluation involves placing a thin wire under the skin in your lower back. The wire is connected to a small external neurostimulator (ENS, the so-called Verify Evaluation System), which you wear on a belt. The Verify™ ENS sends mild electrical pulses through the thin wire to your sacral nerves. Those pulses may get your bladder and/or your bowel working the way it's supposed to. During the evaluation, which typically lasts several days, you can continue many of your daily activities, with caution.


As with any medical treatment, some people may experience some of the following side effects with sacral neuromodulation:2,13

  • Pain where the device is implanted
  • The electrodes change position in the body
  • Infection or skin irritation
  • Technical problems
  • Adverse changes in bowel or bladder function
  • Numbness at the neurostimulator site
  • Undesirable stimulation or sensations.

The number of people with these side effects has been very low2,13 and in almost all cases they were solved. So you need to talk to your doctor about your experience.


  1. Muñoz-Duyos A, Navarro-Luna A, Brosa M, et al. Clinical and cost effectiveness of sacral nerve stimulation for faecal incontinence. Br J Surg 2008; 95: 1037-1043.
  2. Fraser C, Glazener C, Grant, A et al. Systematic review of the efficacy and safety of sacral nerve stimulation for faecal incontinence. Aberdeen: Review Body for Interventional Procedures; 2004. Commissioned by the National Institute for Clinical Excellence.
  3. Tjandra JJ, Chan MK, Yeh CH, Murray-Green C. Sacral nerve stimulation is more effective than optimal medical therapy for severe faecal incontinence: a randomized, controlled study. Dis Colon Rectum 2008; 51: 494-502.
  4. Melenhorst J, Koch SM, Uludag O, et al. Sacral neuromodulation in patients with faecal incontinence: results of the first 100 permanent implantations. Colorectal Dis 2007; 9: 725-730.
  5. Uludag O, Koch SM, van Gemert WG, et al. Sacral neuromodulation in patients with faecal incontinence: a single-centre study. Dis Colon Rectum 2004; 47: 1350-7.
  6. Ganio E, Masin A, Ratto C, et al. on behalf of the GINS group. Sacral nerve modulation for chronic outlet constipation. 7th Int Meeting Coloproctology, Saint Vincent 2002,
  7. Holzer B, Rosen HR, Novi G, et al. Sacral nerve stimulation in patients with severe constipation. Dis Colon Rectum 2008; 51: 524-529.
  8. Schmidt RA, Jonas U, Oleson KA, Janknegt RA, Hassouna MM, Siegel SW, Muñoz-Duyos A, Navarro-Luna A, Brosa M, et al. Sacral nerve stimulation for treatment of refractory urinary urge incontinence. J Urol 1999; 162: 352-357.
  9. Hassouna MM, Siegel SW, Nyeholt AA, Elhilali MM, van Kerrebroeck PE, Das AK, et al. Sacral neuromodulation in the treatment of urgency-frequency symptoms: a multi-centre study on efficacy and safety. J Urol 2000; 163: 1849-1854.
  10. Cappellano F, Bertapelle P, Spinelli M, Catanzaro F, Carone R, Zanollo A, et al. for the Italian Group of Sacral Neuromodulation (GINS). Quality of life assessment in patients who undergo sacral neuromodulation implantation for urge incontinence: an additional tool for evaluating outcome. J Urol 2001; 166: 2277-2280.
  11. Jonas U, Fowler CJ, Chancellor MB, Elhilali MM, Fall M, Gajewski JB, et al. Efficacy of sacral nerve stimulation for urinary retention: results 18 months after implantation. J Urol 2001; 165: 15-19.
  12. Das AK, Carlson AM, Hull M, US MDT-103 Study Group. Improvement in depression and health-related quality of life after sacral nerve stimulation therapy for treatment of voiding dysfunction. Urology 2004; 64: 62-68.
  13. Van Voskuilen AC, Ooerlemans DJ, Weil EH, de Bie RA, van Kerrebroeck PE. Long term results of neuromodulation by sacral nerve stimulation for lower urinary tract symptoms: a retrospective single centre study. Eur Urol 2006; 49: 366-372.

Information on this site should not be used as a substitute for talking with your doctor. Always talk with your doctor about diagnosis and treatment information.

Last updated: 7 Mar 2013

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