Congenital rectal and anal anomalies

　　The occurrence of rectal and anal anomalies is the result of malformation during embryonic development, and there is no significant difference between males and females, except for anatomical differences. The result of the cloaca separation process is that the urachus sinus and anal-rectal sinus are connected, forming high or intermediate position anomalies, resulting in various incomplete rectal and anal development and fistulas between the rectum and the urethra or vagina. The obstruction in the process of anal migration and the incomplete development of the perineum result in low position anomalies, causing anal skin fistulas, anal vestibular fistulas, anal stenosis, and other conditions.

　　Complications such as acute complete low rectal intestinal obstruction symptoms may occur; patients with anal and rectal stenosis may experience difficulty in defecation, constipation, fecal stone formation, secondary megacolon, and other chronic obstruction symptoms. Various malformations of anal and rectal development and fistula between rectum and urethra or vagina may occur. The obstruction in the posterior movement process of the anal and the underdevelopment of the perineum, as a result of malformation, may lead to low malformation, anal skin fistula, anal vestibular fistula, anal stenosis, etc.

　　1. High malformation

　　It accounts for about 40%, boys are more common, and there is often a fistula. However, because the fistula is small, almost all have symptoms of intestinal obstruction. The nervous supply of the pelvic muscles is often defective, and there are also sacral and upper urinary tract malformations. In this type of case, there is a slight indentation at the normal anal position, and the pigmentation is deeper, but there is no anal opening. During crying, the indentation does not protrude outward, and there is no impact when touched with fingers. Girls often have vaginal fistula, the opening is located at the posterior bend of the vaginal wall, the external genitalia also develop poorly, showing an infantile type, feces often flow out from the fistula orifice, and it is easy to cause genital tract infection. Boys often have urinary tract fistula, gas and meconium are excreted from the urethral orifice, and urethritis, balanitis, and upper urinary tract infection can occur repeatedly.

　　2. Intermediate malformation

　　It accounts for about 15%, the blind end of the rectum without fistula is located beside the bulbocavernosus muscle of the urethra or near the lower segment of the vagina, the puborectalis muscle surrounds the distal end of the rectum. In cases with fistula, the fistula opening is located at the bulb of the urethra, the lower segment of the vagina, or the vestibule. The appearance of the anal position is similar to that of high malformation, and defecation can also be done through the urethra or vagina. The probe can enter the rectum through the fistula orifice. The tip of the probe can be felt in the perineum. Rectal vestibular fistula is more common in girls, because the fistula orifice is located in the navicular fossa of the vaginal vestibule, also known as the navicular fossa fistula. The fistula orifice is large, and the baby can basically maintain normal defecation through the fistula orifice in the early stage. It can cause vaginitis or ascending infection.

　　3. Low malformation

　　It accounts for about 40%, the position of the rectum is lower, and it is often accompanied by fistula, rarely accompanied by other malformations. Some are covered by a thin film at the normal anal position, and the color of meconium can be seen dimly. During crying, the diaphragm is obviously protruding outward. Sometimes the anal membrane has been broken, but not completely, and defecation is difficult. In boys, anal skin fistula is accompanied, the canal is filled with meconium and presents a deep blue color, the fistula orifice is located in the perineum, or even further to the scrotal suture, or any part of the tail side of the urethra. In girls, anal vestibular fistula or skin fistula is accompanied, the fistula orifice is located in the anterior vestibule of the vagina or perineum.

　　This disease belongs to congenital developmental abnormality, so it is impossible to prevent the disease directly by the cause. Early detection, early diagnosis, and early treatment are of great significance for indirect prevention of the disease, and genetic counseling should be carried out at the same time. Preventive measures include avoiding consanguineous marriage, carrier gene detection, prenatal diagnosis, and selective induced abortion, etc., to prevent the birth of affected children. During pregnancy, attention should be paid to strengthening the nutritional status of pregnant women, especially the intake of protein and trace elements, and regular ultrasound examination should be carried out to clarify the situation.

　　1. Live tissue examination

　　Take a small piece of tissue from the submucosal and muscular layer of the rectal wall 4 cm above the anal opening, check the number of nerve ganglion cells, and it is found that children with megacolon lack ganglion cells.

　　2. Anal-rectal manometric method

　　Measuring the reflexive pressure changes of the rectum and anal sphincter can diagnose congenital megacolon and differentiate constipation caused by other reasons. In normal children and functional constipation, when the rectum is stimulated by expansion, the internal sphincter immediately relaxes reflexively, and the pressure decreases. In children with congenital megacolon, the internal sphincter does not relax but contracts significantly, causing an increase in pressure. This method may sometimes produce false positive results in newborns within 10 days.

　　3. Rectal mucosal tissue chemical examination method

　　This is based on the hyperplasia of submucosal and muscular nerve ganglion cells in the spastic segment, the continuously released large amounts of acetylcholine and cholinesterase from the enlarged preganglionic sympathetic nerve fibers, which can be measured by chemical methods and found to be 5 to 6 times higher than normal children, which is helpful for the diagnosis of congenital megacolon and can be used for newborns.

　　1. What foods are good for congenital rectal and anal anomalies

　　Eat light and nutritious food, pay attention to dietary balance.

　　2. What foods should congenital rectal and anal anomalies avoid eating

　　Avoid spicy and刺激性 food.

　　The purpose of surgical treatment for external anal sphincter is to reconstruct an anal canal with normal control function. The choice of method and time is determined by various types and the presence of fistula. The treatment principle is to improve the defecation control function after surgery. The pulled-out rectum must pass through the puborectalis muscle ring, and to better identify the puborectalis muscle and urethra, the intermediate and high-grade malformations can be treated with sacrotuberous analoplasty or sacral perineal analoplasty. To minimize the injury to the pelvic nerves during surgery to enhance sensation, the pulled-down rectum must have good blood supply and reach the perineum without tension. The skin should be sutured into the anal cavity to prevent mucosal prolapse, etc., which are the key points. Whether the surgeon has this concept will determine whether the prognosis is good. Nowadays, most doctors advocate that for those who are not suitable for perineal analoplasty, a temporary colostomy should be performed first at birth, and analoplasty should be performed 6 to 10 months later, and the colostomy should be closed 3 months after surgery.