Introduction Bowel dysfunction (BD) affects two thirds of patients with Multiple Sclerosis (MS), with constipation and incontinence often co-existing. Management is largely empirical; however, Peristeen transanal irrigation (PTAI) has been successfully employed in patients with spinal cord injury and spina bifida. We evaluated the effectiveness of PTAI in MS and examined possible predictors of success.

Methods Thirty consecutive consenting patients (26 female, age 48.2 ± 10.8) with MS who failed maximal medical treatment and Biofeedback for BD were entered in the study. They all undertook a one-to-one training session on how to use the device. Primary outcome measures, the Wexner-Constipation and Wexner-Incontinence scores, were prospectively compared pre- and post-treatment. Standard ano-rectal physiology and measurement of rectal compliance with barostat were performed at baseline. Patients post-treatment were classified as Responders or non-Responders on the basis of reduction to below 10 in the relevant Wexner score, and baseline tests and scores were compared between groups to identify predictors of successful treatment.

Results At 12 months follow-up Wexner-Constipation (12 ± 5.5 vs 4.8 ± 5.5, p = 0.001) and Wex-Incontinence (11.1 ± 6.3 vs 5.9 ± 9.1) improved. Sixteen patients (54%) were classified as Responders. Age, disease duration and disability status were not different to non-Responders.

At baseline, Responders had higher Wexner-Incontinence scores compared to non-Responders (13.3 ± 5.7 vs 8.4 ± 6.1 p = 0.037, respectively). Wexner-Constipation scores were similar in both Responders and non-Responders.

Physiology parameters were similar in the 2 groups, except that Responders had a higher Maximum tolerated volume to rectal balloon distension (Resp 272 ± 62 vs non-Resp 205 ± 96 mls, p = 0.0296) and Rectal Compliance (Resp 15.5 ± 3.3 vs non-Resp 10 ± 4.6 ml/mmHg p = 0.003).

Conclusion PTAI helps over 50% of MS who have failed to respond to maximal medical treatment for bowel dysfunction. It appears that a more compliant and capacious rectum and higher baseline incontinence scores predict successful treatment.