From the Guidelines
Contraction rather than relaxation of the puborectalis muscle is indeed compatible with pelvic floor dyssynergia, and intra-anal intrasphincteric injection of Botox (Botulinum toxin) is a viable treatment option for this condition. Pelvic floor dyssynergia is characterized by paradoxical contraction or failure to relax the pelvic floor muscles during defecation, with the puborectalis muscle being a key component. According to the american gastroenterological association medical position statement on constipation 1, biofeedback and relaxation training have been successful in treating pelvic floor dyssynergia, but in cases where these conservative measures fail, Botox injections may be considered. Some key points to consider when using Botox injections for pelvic floor dyssynergia include:
- The procedure typically involves administering 100-200 units of Botox divided among several sites in the puborectalis and external anal sphincter
- The mechanism of action involves Botox blocking acetylcholine release at neuromuscular junctions, causing temporary muscle paralysis that lasts 3-6 months
- Patients may experience temporary incontinence, pain, or bleeding after the procedure
- Botox injections can help break the cycle of muscle spasm and allow for more coordinated defecation, providing symptom relief for patients with pelvic floor dyssynergia.
From the Research
Pelvic Floor Dyssynergia and Botox Treatment
- Contraction rather than relaxation of the puborectalis muscle is a characteristic of pelvic floor dyssynergia, which can lead to obstructive constipation and difficult defecation 2.
- Intra-anal intrasphincteric injection of Botox (Botulinum toxin) has been used as a treatment option for dyssynergic defaecation, with varying degrees of success 3.
- The evidence suggests that Botox injection can reduce pelvic floor muscle tension and improve symptoms in some patients with dyssynergic defaecation 3, 2.
Mechanism of Action
- Botox works by inhibiting the release of acetylcholine, a neurotransmitter that stimulates muscle contraction, thereby reducing muscle spasms and relaxation 2.
- The injection of Botox into the puborectalis muscle can help to relax the muscle and improve coordination during defecation, making it easier to pass stool 3.
Efficacy and Safety
- Studies have shown that Botox injection can be effective in reducing symptoms of dyssynergic defaecation, with symptomatic improvement ranging from 29.2% to 100% 3.
- However, the evidence is limited by heterogeneity in study design, dose, and outcome measures, and more research is needed to fully understand the efficacy and safety of Botox treatment for pelvic floor dyssynergia 3, 2.
- Other treatments, such as biofeedback therapy and pelvic floor muscle training, may also be effective in managing dyssynergic defaecation, and can be used in combination with Botox injection 4, 5.