How should anal fissures be treated? The principle is to soften the stool, keep it open, stop the pain, release the spasm of the sphincter, interrupt the vicious cycle, and promote the healing of the wound. Specific measures are as follows: (a) Keep the stool unobstructed Oral laxatives or paraffin oil to soften and lubricate the stool, increase fibrous food and change the stool habit to gradually correct the occurrence of constipation. (B) local sitz bath Before and after defecation, use 1:5000 warm potassium permanganate coating solution to sit in the bath to maintain local cleanliness. (iii) Anal canal dilation For acute or chronic anal fissures and not complicated by papillary hypertrophy and anterior sentinel hemorrhoids. The advantage is that it is easy to operate, does not require special instruments, and has rapid efficacy, and only requires daily sitz baths after surgery. After local anesthesia, the patient is placed in the lateral position, and the anal canal is dilated with the two index fingers, and then the two middle fingers are gradually inserted to maintain the dilatation for 5 min. After dilatation of the anal canal, the spasm of the anal sphincter can be removed, so the pain can be relieved immediately after the operation. After dilatation, the anal fissure wound is enlarged and opened, drainage is unobstructed, and the superficial wound can heal quickly. However, this method can be complicated by bleeding, perianal abscess, hemorrhoid prolapse and short time fecal incontinence, and the high recurrence rate is its shortcoming. For chronic anal fissures that do not heal over time and for which non-surgical treatment is ineffective, the following surgical treatments can be used 1.Anal fissure excision is to remove the anal fissure and its surrounding triangular skin, and make a shuttle or fan-shaped incision under local anesthesia or lumbar anesthesia to remove all the anterior sentinel hemorrhoids, hypertrophic anal papillae, anal fissures and, if necessary, vertically sever part of the internal sphincter. The advantage of this method is that all lesions are removed, the wound surface is wide, the drainage is smooth, and the granulation tissue is easy to grow from the base, but the disadvantage is that it leaves a large wound surface and the wound healing is slow. 2.Internal sphincterotomyThe internal sphincter has the characteristics of the involuntary circular muscle of the digestive tract and is prone to spasm and contraction, which is the main cause of anal fissure pain. Generally, partial internal sphincterotomy rarely causes fecal incontinence. There are 3 types of methods as follows. (1) Posterior internal sphincterotomy: in the truncated or prone position, under local anesthesia or general anesthesia, the anal fissure is shown by double lobe opening or anoscopy, and the lower edge of the internal sphincter is cut directly through the fissure, from the anal edge to the dentate line, about 1.5 cm long, and the tissues between the internal and external sphincters should also be separated. If there are inflamed anal sinuses, hypertrophic papillae or external hemorrhoids, they can be removed at the same time. The wound is open and heals on its own. However, the wound is slow to heal, and occasionally there is a “locked hole” deformity, which affects the poor function of the anus, this operation is not recommended. (2) Lateral open internal sphincterotomy: After feeling the intersphincter groove, make a 2cm isolated incision in the lateral skin of the anal margin, use curved vascular forceps to reach the intersphincter groove from the incision, reveal the internal sphincter, use two curved vascular forceps to hold the lower edge of the internal sphincter and separate it upward to the dentate line, use scissors to cut off part of the internal sphincter under direct vision and send it for biopsy to confirm whether it is a sphincter, ligate the two severed ends to stop bleeding, and close the skin with The skin is closed with silk sutures. Advantages of this method: the operation is performed under direct vision, the muscle is completely cut, hemostasis is complete, and the tissue can be taken for biopsy. (3) Lateral subcutaneous internal sphincterotomy: After local anesthesia, the intersphincter groove is felt, and the internal sphincter is cut from the outside to the inside with an ophthalmic cataract knife, avoiding penetrating the skin of the anal canal. Advantages of the method: avoids open wounds and reduces pain. The wound heals quickly. Disadvantages: the cut of the muscle is not complete and sometimes bleeding is easy. Marti (1994) advocated the insertion of an ultrasound rotating probe into the rectum of the anal canal in a lateral subcutaneous internal sphincterotomy to check whether the internal sphincter has been cut and its extent immediately after cutting the muscle. Both of these methods allow for the removal of both external hemorrhoids and hypertrophic papillae.