**Chin-Li Chen and En Meng \***

Division of Urology, Department of Surgery, Tri-Service General Hospital, National Defense Medical Center, 325, Section 2, Cheng-Gung Road, Taipei 114, Taiwan; j0921713355@gmail.com

**\*** Correspondence: en.meng@gmail.com; Tel.: +886-2-87927169

Received: 31 December 2019; Accepted: 7 February 2020; Published: 10 February 2020

**Abstract:** Chronic pelvic pain (CPP) is defined as chronic pain and inflammation in the pelvic organs for more than six months. There are wide ranges of clinical presentations, including pelvic pain, painful intercourse, irritable bowel syndrome, and pain during urinating. Chronic pelvic pain syndrome (CPPS) is a subdivision of CPP, and the pain syndrome may be focused within a single organ or more than one pelvic organ. As there is uncertain pathogenesis, no standard treatment is currently available for CPPS. Botulinum toxin A (BoNT-A) is a potent neurotoxin that blocks acetylcholine release to paralyze muscles. Intravesical BoNT-A injection can reduce bladder pain in patients with interstitial cystitis/bladder pain syndrome. BoNT-A injected into the pelvic floor muscles of women has also been reported to improve chronic pain syndrome. Due to the reversible effect of BoNT-A, repeated injection appears to be necessary and effective in reducing symptoms. Adverse effects of BoNT-A may worsen the preexisting conditions, including constipation, stress urinary incontinence, and fecal incontinence. This review summarizes the evidence of BoNT-A treatment for CPPS in animal studies and clinical studies regarding the therapeutic effects of BoNT-A for CPPS in female patients.

**Keywords:** botulinum toxin A; chronic pelvic pain syndrome; pelvic pain

**Key Contribution:** We have reviewed the current basic and clinical evidence of BoNT-A injections for treating CPPS in female patients. This treatment is safe and effective and should be considered as a standard treatment for female CPPS.
