Surgery for rectal cancer has saved countless lives. However, many patients discover that even after cancer is cured, their bowel function never feels the same. This group of symptoms is known as LARS — Low Anterior Resection Syndrome.
What is LARS?
LARS is a chronic bowel dysfunction that may develop after sphincter-preserving rectal surgery. The international consensus definition highlights that LARS includes bowel symptoms that significantly impact quality of life.
Common symptoms include:
- Bowel urgency
- Frequent bowel movements
- Clustering (multiple bowel movements within a short time)
- Feeling of incomplete emptying
- Fecal incontinence or leakage
- Unpredictable bowel function
More important than individual symptoms is their impact on daily life: fear of leaving home, toilet dependence, social and work limitations, and intimacy concerns.
Why does LARS happen?
After rectal surgery, the natural stool reservoir is reduced and pelvic nerves may be affected. Radiotherapy can also alter bowel motility and sensitivity. The result is a bowel that empties more urgently, more frequently, and in a fragmented way.
How do we treat LARS?
Treatment is stepwise and individualized:
Initial measures
- Dietary adjustments
- Medications to reduce urgency and frequency
- Pelvic floor physiotherapy
- Bowel retraining
Transanal irrigation
Allows scheduled emptying of the bowel, reducing urgency and clustering.
Sacral neuromodulation (SNM)
When symptoms persist despite conservative therapy, sacral neuromodulation becomes an important option.
SNM uses a small implanted device that modulates the nerves controlling bowel function. Clinical trials show SNM can:
✔ Reduce urgency
✔ Decrease fecal incontinence episodes
✔ Reduce clustering
✔ Improve sense of complete evacuation
✔ Significantly improve quality of life
The randomized SANLARS trial demonstrated sustained improvement in bowel symptoms and quality of life in patients with severe LARS treated with sacral neuromodulation 00003453-202403000-00014.
When should SNM be considered?
It is mainly indicated for patients with:
- Severe LARS
- Failure of medical and rehabilitative treatments
- Major impact on quality of life
SNM is minimally invasive, adjustable, and reversible, and in some cases may help avoid a permanent stoma.
Keep in mind
LARS is not something patients simply need to “live with.” It is an internationally recognized condition with effective treatments available. If bowel function changed after rectal surgery, specialized evaluation can make a major difference.