It can. If the pain is due to muscle spasms, Botox could help.
Not usually. Botulinum toxins are used to temporarily relax muscles-particularly the ones that cause eye and face twitches; neck spasm; TMJ & even migraine headaches, plus cosmetic uses for facial, neck and chest muscles and excess sweating of the armpits, hands and feet. Btx has been used off-label for relaxing the anal sphincter for patients with spasm from hemorrhoids and fissures though.