I. What is hemorrhoid? In humans, there is a ring-shaped tissue zone above the dentate line in the anal canal about 15mm-20mm wide, which is usually called the hemorrhoid area or rectal column area. Embryologists call this area “a cavity anal source area”. The unified name in the anorectal surgery and anatomy community is anal pad. Due to the contraction of the internal sphincter, the anal cushion is divided into three pieces: the right anterior, the right posterior and the left side by a “Y” shaped groove. The normal anal cushion is like the tricuspid valve of the heart, and its main function is to assist the sphincter to ensure the normal closure of the anus and to maintain fecal self-control. Hemorrhoids are defined as pathological hypertrophy and displacement of the anal cushion. This definition is the basis for a new understanding of hemorrhoids. The traditional understanding of hemorrhoids is based on the “varicose vein theory”, which states that hemorrhoids are rich meridians in the lower rectum or anal canal, which become hemorrhoids if they dilate or varicose in one or several places, i.e. hemorrhoids are prominent varicose vein masses, which are lesions of the blood vessels themselves caused by various reasons. . In contrast to this concept, the traditional diagnosis, classification, staging and treatment of hemorrhoids also focus on the pathology of “varicose veins from” this understanding. The modern concept of hemorrhoids is based on anatomy, histology and physiology, studying the relationship between tissue anatomy and physiological changes and the formation of hemorrhoids. At present, most scholars believe that “anal cushion” is the “vascular lining” of the anus, which is part of the rectal anatomy and is a normal structure that everyone has, and cannot be considered a disease. “hemorrhoids”. Foreign scholars and our scholars still classify internal hemorrhoids into four degrees (or four stages) from the convenience of various therapies, i.e. comparison, evaluation and preference of efficacy, and this classification is mainly based on the degree of hemorrhoid prolapse: Ⅰ degree – internal hemorrhoids are located in the anal canal; Ⅱ degree – internal hemorrhoids can prolapse outside the anus during defecation, but can be returned by themselves; Ⅲ degree -Prolapsed in the natural state or during defecation, and need to be returned with the help of hands; Ⅳ degree -Prolapsed and cannot be returned. The principle of PPH is to use the anastomosis to remove the rectal mucosa above the hemorrhoid and complete the incision anastomosis simultaneously, so that the prolapsed anal cushion can be retracted and reset, the local anatomical relationship between the anal canal mucosa and sphincter can be restored, the self-control function of the anus can be improved, the internal pressure of the anal canal can be reduced, and the symptoms of hemorrhoid prolapse can be eliminated; the anal cushion tissue is not destroyed, and the recognition function of the anal canal rectum on the intestinal contents is preserved. And avoid the occurrence of postoperative anal stenosis, incontinence and fine stool control dysfunction; cut off the branch of the superior rectal artery to the hemorrhoid nucleus, reducing the blood supply to the hemorrhoid nucleus, shrinking the hemorrhoid nucleus, which can reduce the damage stimulation of the mucosa by the fecal mass and remove the main cause of bleeding from the hemorrhoid nucleus; because the anastomosis is located in the area of 1.5cm~2.0cm above the dentate line, there are few somatic sensory nerves in this area, so the postoperative anal pain is not obvious . IV. Indications PPH is mainly suitable for: II degree hemorrhoids with severe bleeding or anemia, III-IV degree prolapsed hemorrhoids. The current status Because of the advantages of simple operation, short operation time, less bleeding at the end of operation, significant reduction of preoperative symptoms, short hospitalization time, “one-day operation”, light postoperative anal pain, short time, few long-term complications, quick recovery after operation, no narrowing of the anus, no recurrence of hemorrhoids, etc., PPH has been accepted by more and more clinical It is accepted by more and more clinical workers and patients. The only drawback is that it is expensive, cannot be used repeatedly, and is difficult to perform in economically underdeveloped areas.