Instructions: In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.
Input: Context: Controversy has surrounded the technique of circular stapled anopexy since an isolated report of a high incidence of persistent postdefaecation pain following the procedure. The characteristics, clinical course and management of this complication have not been described.', 'Within an ongoing multicentre randomized clinical trial comparing circular stapled anopexy with closed haemorrhoidectomy, 77 patients underwent circular stapled anopexy. Follow-up was at 6, 12, 24 and 48 weeks. Patients underwent transanal ultrasonography, anal electrosensitivity testing and manometry.', 'Of the 77 patients who had circular stapled anopexy, three men reported new-onset postdefaecation pain that compromised lifestyle, including ability to return to work. All three had sphincter hypertonicity on digital and manometric examination but were refractory to topical 0.2 per cent glyceryl trinitrate ointment. The addition of oral nifedipine 20 mg twice daily did not alter anal sphincter pressures but rapidly abolished symptoms and restored quality of life.\Question: Is postdefaecation pain syndrome after circular stapled anopexy abolished by oral nifedipine?
Output:
Postdefaecation pain is a specific complication of circular stapled anopexy, affecting a small percentage of patients. Men with a high anal sphincter pressure appear to be at risk. Although the exact aetiology remains unclear, it is likely that rectal rather than anal sphincter muscle is affected. Oral nifedipine represents an effective therapy.