Living with poor bowel control changes has a massive impact on people’s daily lives. They map out toilets before leaving home, pack spare clothes, and sometimes skip social events altogether. So when someone finally sits down with a colorectal surgeon in Melbourne to talk about nerve stimulation, they usually want one straight answer: which option actually works? Two treatments come up most often. Percutaneous tibial nerve stimulation (PTNS) uses a fine needle near the ankle to send gentle pulses along the tibial nerve. Sacral nerve stimulation (SNS), also called sacral neuromodulation, places a thin electrode near the sacral nerve roots and connects it to a small implanted battery. Both target the nerve pathways controlling the pelvic floor and anal sphincter. Both have a place in faecal incontinence treatment. The evidence behind them, though, looks very different.
What the CONFIDeNT Trial Changed
For years, tibial nerve stimulation looked promising. Small studies reported good results, and the appeal was obvious. No surgery, no implant, minimal risk.
Then the CONFIDeNT trial arrived. Published in The Lancet in 2015, this UK multicentre study randomised 227 adults with faecal incontinence to either genuine PTNS or a placebo treatment. Participants received twelve weekly sessions. Neither group knew which treatment they were getting.
The results surprised a lot of clinicians. Around 38% of the PTNS group achieved at least a 50% reduction in weekly incontinence episodes, compared with 31% in the placebo group. That difference wasn’t statistically significant. In plain terms, real tibial nerve stimulation didn’t clearly beat a convincing placebo.
The trial was well designed and adequately powered, which makes the finding hard to dismiss. Later reviews, including Cochrane analyses, reached similar conclusions about the weak evidence base for PTNS in bowel dysfunction.
How Sacral Nerve Stimulation Compares
Sacral nerve stimulation carries a much stronger track record. Long-term follow-up studies consistently report that 70% to 80% of patients maintain significant improvement, with many achieving complete continence.
A landmark five-year multicentre study by Hull and colleagues followed 120 patients and found 89% still had at least 50% improvement in incontinence episodes. Median episodes dropped from over nine per week at baseline to fewer than two. Australian centres have reported comparable outcomes, and SNS is funded under Medicare and private health cover for suitable candidates.
The other advantage is the trial phase. Patients wear a temporary external device for two to three weeks before committing to a permanent implant. If symptoms don’t improve, the wire comes out and nothing further happens. This test-drive approach means very few people end up with a permanent device that doesn’t help them.
Weighing Up the Practical Differences
Tibial nerve stimulation involves:
- A fine needle placed near the ankle during a straightforward outpatient visit
- Twelve weekly sessions, followed by ongoing maintenance treatments
- A weak evidence base, with negative results from randomised controlled trial data
- Success rates that match placebo treatment
- Minor risks such as bruising and temporary discomfort
- Repeat clinic visits that continue indefinitely
Sacral nerve stimulation involves:
- A surgical implant performed in two stages, starting with a temporary trial
- One procedure, with a battery that lasts several years
- Strong evidence, backed by long-term cohort data
- Sustained improvement in roughly 70% to 80% of patients
- Surgical risks including infection, lead migration and pain at the implant site
- Programming reviews and eventual battery replacement
Cost matters too. PTNS looks cheaper upfront, but repeated sessions add up, and maintenance is often needed indefinitely. SNS costs more initially and delivers better durability.
Best Practice Before Any Nerve Stimulation
Neither treatment should be the first step. Good care starts with proper assessment: anorectal physiology testing, endoanal ultrasound to check sphincter integrity, and often a defecating proctogram.
Conservative measures come next. Dietary changes, fibre adjustment, loperamide, and supervised pelvic floor physiotherapy with biofeedback help a substantial proportion of patients, helping them potentially avoid surgical procedures entirely.
Sphincter repair may suit people with an obvious obstetric injury. Structural problems like rectal prolapse need addressing first, since fixing the prolapse often fixes the continence.
Choosing the Right Faecal Incontinence Treatment with a Colorectal Surgeon in Melbourne
The evidence points clearly toward sacral nerve stimulation as the more reliable option for moderate to severe bowel control problems. CONFIDeNT showed tibial nerve stimulation performs no better than placebo, while SNS delivers durable improvement for most patients who pass the trial phase. That said, the best faecal incontinence treatment depends on the person, their anatomy, their test results, and what they’re willing to take on. A thorough assessment with a colorectal surgeon in Melbourne sorts out which pathway makes sense and often uncovers simpler solutions along the way.
