Nitroglycerin ointment can promote the healing of anal fissure, not necessarily a cure, due to individual differences, no method can necessarily cure anal fissure. Anal fissure can be caused by constipation or diarrhea, anal trauma, childbirth laceration and other reasons, can appear perianal pain, blood in the stool and other symptoms, the application of nitroglycerin ointment can relax the internal anal sphincter, promote the healing of the fissure area, relieve pain. However, due to the patient’s physical condition, the severity of the disease and other factors, the use of nitroglycerin is not necessarily able to cure anal fissure, so the specific time to cure anal fissure can not be determined. In addition, it should be noted that the use of nitroglycerin ointment may cause headache, nausea, vomiting, skin allergies, rapid heartbeat and other adverse reactions. 18 years of age or younger, recurrent headache, moderate anemia, migraine, cerebral blood supply insufficiency and other people are prohibited from use. Note that contact with the mucous membranes of the mouth and nose and eyes and other parts of the body should be avoided during the use of the drug, and should not be taken orally. Patients with anal fissure should consult the doctor in time, under the guidance of the physician for treatment, do not self-medication, to avoid causing adverse consequences.