I am a 54 y o male. I have a posterior anal fissure since april 8th following a violent diarrhea . Almost 6 months so far. I have used nifedipine for 6 weeks, but the wound did not heal. I underwent a colonoscopy and nothing was found. Tested for HIV , syphilis, parasites and tubercolosis. All negative. I have not a hypertonic internal sphincter according to two anal manometry I underwent. Those two exams (I did not trust the doctor that performed the first one) showed paradoxical reflex. My doctor refuses to do the sphicterotomy because he fears I may develop fecal incontinence. He told me to look for another opinion. Another doctor said that anal fissure caused by diarrhea are typical of paradoxical reflex, and that the only treatment available for this is physioterapy (biofeedback). I could not find this in medical literature. What do you think?