The perianal region is the region around the anus. Administering a pain medication before a surgery starts is called preemptive analgesia. In some studies, this technique has been shown to be an effective way to reduce the pain that a patient experiences in the post-operative timeframe to a greater extent than would be expected simply from the pain medications alone. One theory of why this occurs suggests that the preemptive analgesia desensitizes brain and nerves to pain, thereby decreasing the response to painful stimuli, like surgery when they occur. This leads to a decrease in the amount of narcotic pain medication required after the procedure, which leads to less side effects and a quicker return to normal functioning. As perianal surgeries do not usually include a long stay in the hospital, controlling post-procedure pain is a priority.