In recent years, with the increasing understanding of the nature of hemorrhoids and the mechanism of hemorrhoids, the treatment of hemorrhoids has undergone a great change in both concept and method. The traditional concept is that the three mucosal masses located above the dentate line in the right front, right back and left center are abnormal structures, i.e., internal hemorrhoids, so there are “nine hemorrhoids in ten men and ten hemorrhoids in ten women”. In 1975, Thomson first proposed the theory of anal cushion based on his research results, that is, the traditional concept that the anal cushion is actually the anal canal. It is not a pathological venous mass formed by local varicose veins due to various reasons as previously thought, but a vascular mass composed of special arteriovenous traffic, which is similar to veins in appearance but has no muscular layer in its vascular wall, so unlike veins, this vascular mass has a vascular spongy body-like effect and is important for fine stool control. In 1994, Loder further proposed the theory of subluxation of the anal cushion in internal hemorrhoids, that is, it occurs due to injury or rupture of the Treitz muscle and Park ligament, the suspensory ligaments that hold the anal cushion in place, resulting in prolapse and subluxation of the anal cushion. Based on the above understanding, in recent years, more and more scholars have abandoned the concept of treating every hemorrhoid, and only treat symptomatic internal hemorrhoids instead. The surgical method has changed from removing the hemorrhoids as thoroughly as possible anatomically in the past to resetting the prolapsed anal cushion through surgery and preserving the structure of the anal cushion as much as possible in the process of surgery in order to achieve the goal of not affecting or affecting as little as possible the ability of fine stool control after surgery. The surgical treatment of hemorrhoids mainly focuses on symptomatic III and IV degree prolapsed internal hemorrhoids and mixed hemorrhoids, especially circumferential prolapsed internal hemorrhoids. In 1998, according to the new theory of internal hemorrhoid formation, Italian scholars Long et al. reported a new method of circumferential resection of the mucosa and submucosa of the lower rectum to treat stage III and IV circumferential prolapsed internal hemorrhoids – anastomotic hemorrhoidectomy (procedure for prolapse and hemorrhoidectomy). The procedure for prolapse and hemorrhoids (PPH). Because this procedure is physiological, simple, and has few postoperative complications, it has been rapidly and widely used at home and abroad. 1, external stripping and internal ligation was first proposed by Miles in 1919, and in 1937, St. Mark’s Hospital in England, Milligan and Milligan were the first to perform the procedure. The procedure was modified by Milligan and Morgan at St. Mark’s Hospital in England in 1937, and is now generally known as Milligan-Morgan procedure or external peel and tie procedure, which is the most commonly used procedure in clinical practice. The main point of this procedure is to make a V-shaped incision at the junction of the skin and mucosa at the lower pole of the hemorrhoid with the tip pointing outward, peel upward along the surface of the internal sphincter to the root of the hemorrhoid mass, ligate with local sutures, and remove the hemorrhoid tissue. The advantage is that the procedure is simple and effective in the eradication of single or relatively isolated internal hemorrhoids. The disadvantage is that only a maximum of 3 hemorrhoids can be removed at a time, and a certain mucosal bridge needs to be preserved between the trauma of the 3 removed parent hemorrhoids, otherwise it is easy to cause anal stenosis after surgery, and the recurrence rate after surgery can be about 10%. In addition, the postoperative period is often accompanied by significant edema in the anal region, which is painful and prolonged; the wound healing is slow and usually takes 3~4 weeks; if too much tissue is removed, the postoperative period can be accompanied by a certain degree of anal incontinence or anal stenosis. In order to reduce postoperative anal pain, many scholars have tried many new methods in recent years, such as partial excision of the lateral internal sphincter while removing hemorrhoids, using electric knife or laser knife instead of scissors or ordinary scalpel to cut the skin, and one-stage suturing of the traumatic skin during surgery to shorten the healing time of the postoperative trauma, but the results are not obvious. 2.Circumferential hemorrhoidectomy was first reported by Whitehead in 1882, mainly for annular prolapsed internal hemorrhoids or annular mixed hemorrhoids, and was later improved by Saresola and Klose in the 1940s, and is now generally known as the Saresola-Klose method or the Klose method, also known as the Whitehead method. The basic point of the procedure is to separate the lower rectal mucosa, submucosal tissue and all hemorrhoid tissue at 0.3-1.0 cm above the dentate line along the surface of the internal sphincter muscle and remove it in a circular fashion about 2-3 cm wide, and then suture the rectal mucosa to the mucosal skin of the anal canal. The advantage is that the hemorrhoid block is completely removed and the recurrence rate is low after the operation, but the disadvantage is that the operation takes a long time, there is a lot of bleeding during the operation, and 10%-13% of the patients have more serious complications after the operation, such as anal canal stenosis, mucosal ectasia, sensory incontinence due to loss of sensation in the anal canal, etc., which is less used nowadays. 3, clutch hemorrhoidectomy (PPH) Clutch circumferential hemorrhoidectomy, also known as suprahemorrhoidal mucosal ring excision, anal cushion suspension. The essence of hemorrhoid surgery such as anastomosis is to preserve the integrity of the anal cushion, and to remove the mucosa and submucosa tissue of the lower rectal wall in a circular fashion above the hemorrhoid through a specially designed anastomosis (in principle, the hemorrhoid mass is not removed, but the upper part of the hemorrhoid can be removed at the same time for large hemorrhoid masses and severely prolapsed circumferential hemorrhoids), while the distal and proximal mucosa is anastomosed so that the prolapsed internal hemorrhoid is suspended and pulled upward and no longer prolapses. Since the arteries supplying the hemorrhoid located in the submucosa are cut at the same time, the blood supply to the hemorrhoid is reduced after surgery and the hemorrhoid mass gradually shrinks about 2 weeks after surgery. The main indications for this procedure are grade III and IV circumferential internal hemorrhoids or mixed hemorrhoids with mainly internal hemorrhoids. Although the procedure is also effective for grade II internal hemorrhoids and isolated prolapsed internal hemorrhoids, it is generally not used because of the high cost of the special clutch required for the procedure. The advantages of this procedure over conventional surgery are: (1) The procedure is simple and the operative time is short, usually 8-15 min on average, with minimal intraoperative bleeding. (2) The treatment of prolapsed circumferential internal hemorrhoids and bleeding caused by hemorrhoids is effective: if the distance between the site of the purse-string suture and the tooth line is appropriate, the prolapsed hemorrhoids can be seen to retract into the anal canal immediately after the intraoperative removal of the anastomosis. Although a small amount of blood in the stool can be seen in about 1.7%-33.0% of patients in the early postoperative period, 93%-100% of patients with intermediate and long-term follow-up had disappearance of preoperative internal hemorrhoid prolapse and anal bleeding. The authors performed this surgery in 52 cases with 1~10 months follow-up, and 98% of the patients were satisfied with the surgical results after surgery, and the symptoms of preoperative bleeding, prolapse, and perianal dampness disappeared. (3) The postoperative pain in the anal region was mild and short. Since there is no trauma to the anal skin and edema common after external peel and ligation, although about 30% of patients complained of anal pain after surgery, the degree and duration of pain were shorter than those of Milligan-Morgan surgery, with an average of 2 days for the former and 6 days for the latter. (4) The postoperative hospital stay was short and the return to normal life and work was early. The average postoperative hospital stay was generally 1 to 4 days, and 3.5 days in the author’s unit case. Due to the low postoperative complications of this procedure, some authors have recently tried to perform this procedure on an outpatient basis without hospitalization, and normal life and work can be resumed in about 7 days after surgery. (5) Few long-term complications: except for Ho et al. who reported mild anal incontinence in 2 of 57 cases after surgery, no complications such as anal stricture and fecal incontinence occurred in the literature. According to the authors and the limited literature, the common postoperative complications are: (1) urinary retention: the incidence is about 40%~80%, more in men than in women, and patients with lumbar anesthesia are significantly higher than those with sacral or local anesthesia, which may be related to anesthesia and The occurrence may be related to anesthesia and postoperative anal pain stimulation. (2) Anal pain: Theoretically, there is no trauma to the perianal skin during PPH surgery, and there should be no anal pain after surgery, but due to sufficient anal dilation during surgery, it often causes tearing of the anal canal skin. In addition, the clamping of the perianal skin during the operation may also be the cause of postoperative anal pain, but the pain time and pain level are obviously lighter compared with external peeling and internal ligature surgery, mainly on the night of the operation and can be relieved the next day, and generally no analgesic is needed. (3) Lower abdominal pain: About 10% of patients complained of a pulling sensation in the lower abdomen during the anastomotic stroke, and individual patients even vomited. About 15% of patients complain of lower abdominal distension on the day after surgery. The exact mechanism of occurrence is not clear, but may be related to the pulling reflex of the intestine during anastomosis, which generally does not require special treatment and can be relieved on its own the day after surgery. (4) Bleeding: There are two cases, one is intraoperative anastomotic site bleeding, in a group of surgical patients of the authors, about 30% of patients can see pulsatile bleeding at the anastomotic site after anastomosis, most of them are located at the site of 3 parent hemorrhoids, especially the right anterior part of the anastomosis is most common, followed by the right posterior and left median parts. The site, amount and severity of pulsatile bleeding from the anastomosis are related to the distance of the anastomosis from the dentate line, the higher the distance the less bleeding; on the contrary if the anastomosis is closer to the dentate line, i.e. if the anastomosis is located in the middle of the internal hemorrhoid (part of the internal hemorrhoid is removed), the bleeding is more, the reason for which is related to the abundance of blood vessels near the dentate line. For fluctuating bleeding the authors routinely use local sutures to stop the bleeding, but in the early years of the method many authors did not pay enough attention to this, and it has been reported that about 10% of patients need local hemostasis again after surgery, and some patients even have severe hemorrhagic shock due to local bleeding. Therefore, the authors emphasize the importance of carefully checking the anastomosis for fluctuating bleeding after intraoperative anastomosis and treating it accordingly. The other is postoperative blood in the stool. Most patients have less bleeding, which can last for about 1 week, and the bleeding is relatively small and does not require special treatment. (5) Sensory disturbance in the anus: If the anastomosis is too close to the dentate line, some patients experience localized cramping and swelling in the early postoperative period, and even cannot feel the fecal discharge and experience mild fecal incontinence, which usually recovers about 2 weeks after surgery. (6) Infection: Molloy reported one case of postoperative pelvic infection and caused death. (7) Rectovaginal fistula: Roos reported a case of rectovaginal fistula due to local infection of the anastomosis. (1) Moderate position of the purse-string suture: Generally, it should be about 3~4 cm above the dentate line, i.e., the anastomosis is 1~2 cm above the dentate line; too low a position of the purse-string suture will result in excessive removal of the anal cushion, easy bleeding at the anastomosis during and after surgery, early postoperative sensory impairment of the anal canal, and sensory fecal incontinence; while too high a position of the purse-string suture will reduce the upward pull and suspension of the anal cushion. The retraction of hemorrhoid nucleus is not obvious or even ineffective. (2) Depth of purse-string suture: The depth of purse-string suture should be in the submucosa, too shallow suture is easy to cause tearing of mucosa when pulling, and it has been reported that some patients have incomplete resection circle, which may be caused by too shallow suture in part of the position when purse-string suture is closed, and local mucosa tearing when knotting or pulling, and the mucosa in the area is not effectively removed. If the suture is too deep, it is easy to damage the internal anal sphincter causing postoperative anal incontinence. (3) The suture ligature should not be too tight, otherwise the intestinal wall is tightly bound to the central rod of the anastomotic ring, which affects the downward pulling. (4) The number of purse-string sutures should be determined according to the degree of prolapse. In Longo and later reports in the literature, a single purse was used, but the authors found that the resected specimens were more unevenly shaped when a single purse was made, i.e., more tissue was resected at the site of suture traction and less tissue was resected on its opposite side. In addition, the narrow width of the resected tissue was not effective in patients with severe prolapse. According to the authors’ experience, the upper and lower width of resection of the intestinal wall is related to the degree of downward suture pull, the number of purse-string sutures, and the distance between the two purse-string lines. The wider the distance between the two pouches, the wider the upper and lower width of the resected tissue. Therefore, the width of resection of the intestinal wall should be based on the severity of internal hemorrhoid prolapse, and patients with severe prolapse should have a wider width of resection accordingly, so that they can do 2 pouches and traction deeper into the anastomosis. Conversely, patients with mild prolapse can have only 1 purse-string suture. For patients with asymmetric prolapse, one and a half purse-string traction can be added to the more severe side of the prolapse to allow for more resection in that area. (5) In female patients, the retraction line should be avoided to be located on the anterior rectal wall, while the posterior vaginal wall should be checked to see if it is retracted into the anastomosis before closing the anastomosis and the anastomosis is struck to prevent damage to the posterior vaginal wall and cause rectovaginal fistula. In conclusion, with the increasing understanding of the mechanism of hemorrhoids and the anatomy of the anorectum, the methods of hemorrhoid surgery are being improved, with the aim of focusing on how to be more physiological, reduce postoperative pain while reducing or eliminating preoperative symptoms, shorten postoperative hospital stay, and reduce possible postoperative complications, and anastomotic hemorrhoidectomy as a new method although preliminary results show that it has many advantages over traditional surgical Although the preliminary results of anastomosis as a new method show that it has many advantages compared with traditional surgery, the long-term results are yet to be observed in further follow-up due to the short time of implementation.