Patients will be enrolled in cohorts. Within the first 5 cohorts, 8 patients are to receive BOTOX and 2 patients to receive placebo. For cohort 6, 12 patients will receive BOTOX and 12 patients will receive placebo. Patients will receive a single treatment of study medication delivered bilaterally to the bulbospongiosus muscle. The initial BOTOX total dose in this dose escalation study will be 5 U and the maximum BOTOX total dose will be 100 U. Upon request and if eligible, patients in cohort 6, will have the option to receive a second injection of BOTOX (open label).