Swelling and pain in the anterior hemorrhoid of anal fissure may be due to inflammatory stimulation, obstruction of lymphatic reflux and other reasons. 1. Inflammatory stimulation: the inflammatory secretion produced by anal fissure repeatedly stimulates the lower end of the fissure, resulting in edema, which in turn causes swelling and pain. 2. Lymphatic reflux obstruction: under the action of inflammatory factors, lymphatic reflux is obstructed, which aggravates edema, and then you feel swelling and pain. 3. long-term constipation: dry stools, constipation, resulting in skin damage, and then the formation of anal fissure, the ulcerated surface is repeatedly stimulated, inflammatory hyperplasia, will also be obvious swelling and pain, and then gradually formed sentinel hemorrhoids. The phenomenon of anal fissure sentinel hemorrhoid swelling and pain, it is best to go to the regular hospital in time, a clear diagnosis, and then under the guidance of a professional doctor for treatment, so as not to delay the condition, affecting the normal life.