Anal fissures are fissures that occur in the entirety of the skin of the anal canal. The cause is mostly due to dry stools. It occurs mostly in the front or back of the anus. It can affect both men and women, young and old. Anal fissures present with pain and bleeding. The pain is characteristic, i.e., a sudden cut-like pain during defecation (due to feces cutting through the skin of the anal canal), followed by a brief relief due to the termination of defecation, and then a prolonged anal pain (due to spasm of the anal sphincter after stimulation). The pain of anal fissure occurs only during defecation, and the pain basically disappears after defecation, but in recurrent episodes, there is also a burning pain after defecation, which usually lasts for 20 to 30 minutes, and in severe cases, up to half a day or more. Why does it hurt twice? The initial pain is caused by the expansion of the anus by feces, and the second pain is caused by the spasm of the anal sphincter produced by the first stimulation, which is transmitted through the nerves to the waist, hip and lower limbs, so some people have difficulty urinating and abdominal pain. Patients are afraid to defecate for fear of pain, and a vicious cycle of “fear of pain —- tolerate stool —- stool dry —- more pain” occurs. The early onset of anal fissures can be completely cured by conservative treatment. If you have to use a coarse fiber diet or laxatives to soften the stool, with topical medication or Chinese herbal baths, and if you ask a specialist to help you put on drainage strips at the same time, you will recover even faster, usually within a week. If anal fissures are not treated in a timely manner in the early stage, ulceration of the anal canal (fissure fibrosis, also known as old anal fissures) with enlarged anal papillae (polypoid tumors) and sentinel hemorrhoids (dermal hyperplasia) may occur. For chronic recurrent anal fissures, manual or surgical treatment is recommended. Manual treatment, i.e. anal dilation, can heal old anal fissures, but not with anal papilloma and sentinel. Spasm of the anal sphincter makes the fissure deeper and the wound ulcerates and erodes. Once the ulcer is formed, the feces remaining in the ulcer becomes easily infected. After infection, the erosion surface expands upward, downward, and deeper, and the inflammation spreading upward from the ulcer stimulates tissue proliferation to form an anal papilloma, which can sometimes prolapse outside the anus. At the same time, the downward spreading inflammation stimulates the production of small redundant skin near the anal outlet, as if it were a sentry around the anus, hence the name sentinel hemorrhoid. In severe cases, the inflammation can become purulent, break down into the skin and form purulent sinus tracts. Anal fissures develop into anal ulcers, and there are often many adverse factors. Anal ulcers can lead to anal stricture, and surgery can be expected to restore normal bowel function. Anal ulcers cannot be cured by life therapy of relieving constipation alone and must be treated surgically. Therefore, initial anal fissures can be treated without surgery, but old anal fissures need to be treated surgically, and as early as possible.