Anorectal malformations are commonly referred to as “anorectal” and “anal atresia”, and abnormal anorectal development usually occurs between 5 and 7 weeks of gestation. The incidence of anorectal malformations is greater than 1 in 5000 births, with a slightly higher rate in males, and the cause is not known. Some environmental abnormalities or drug effects may be found in some patients, but are not definitive. During defecation, the stool is passed through the large intestine and rectum with the anal canal. The nerves of the anal canal sense the need to defecate and govern the activity of the muscles that control the process of defecation. In children with anorectal malformations, these nerves and muscles also have varying degrees of developmental abnormalities. Manifestations of anorectal malformations The anal opening is narrow or located anterior to its normal position. The anal opening is covered by a membrane. The rectum does not communicate with the anus. The end of the rectum is connected to the urinary or genital tract in a tube called a “fistula”, without an anal opening. The consequences of anorectal malformations vary depending on the type and severity of the malformation: If the anus is narrow or opens in front of the normal position, the child may have difficulty defecating, causing constipation and bowel discomfort. If there is a membrane covering the anus, the child cannot defecate until the surgery. If the rectum does not communicate with the anus and there is no fistula (abnormal connection to the genital or urinary tract), defecation is not possible, resulting in bowel obstruction. Comorbidities of anorectal malformations Approximately 50% of children have other comorbidities, including: spinal malformations such as hemivertebrae, missing vertebrae, spinal cord embolism Renal and urinary anomalies, such as horseshoe kidney, duplicated kidney. Congenital heart disease. Tracheoesophageal malformations. Limb (especially forearm) deformities. Down’s syndrome, congenital megacolon, duodenal atresia, etc. Diagnosis of anorectal malformations Abnormalities in the opening and position of the anus can be detected by physical examination after birth. To further define the type of anomaly and the presence of combined anomalies, additional tests may be needed: abdominal x-ray, which can provide a rough indication of an anatomical anomaly of the rectum (atresia “high” or “low”), as well as the presence of spinal and sacral anomalies. Abdominal ultrasound and spinal ultrasound: examines the urinary system and spine, and can also help to understand the presence of spinal cord tethering. Spinal cord embolism may lead to neurological symptoms such as incontinence and weakness of the lower extremities during growth. Echocardiography: To find out if there is congenital heart disease. Magnetic resonance imaging (MRI): Used in some patients to diagnose spinal cord embolism or other spinal deformities. It can also help to understand the pelvic muscles and structures. Surgery for anorectal malformations. The choice of treatment is determined by the type of anorectal deformity, the presence of comorbid malformations and the general condition of the child. The vast majority of children require surgery. Children with recto-perineal fistulas require trans-perineal anoplasty to move the anus to a normal position (within the sphincter). Children with anorectal malformations without a combined fistula or a combined urinary or genital fistula may require one or more procedures. A colostomy is usually performed first. During a colostomy, the colon is dissected and the two ends are removed through a small incision in the abdominal wall, the proximal end to drain the stool and the distal end to drain the mucus from the lower intestine. After receiving the fistula, feeding and growth are not affected before the next surgery. The diversion of stool minimizes the likelihood of future infections after reconstructive surgery. The fistula requires special care, but it is not difficult, and parents will be given detailed instructions by the medical staff. The second surgery will reconstruct the anus, and the incision is usually made in the midline of the buttocks. Some children have a relatively high rectal end and may have an open or laparoscopically assisted procedure. The anoplasty is performed without sealing the fistula, and feces will still be drained through the fistula opening to ensure that the area is free of fecal contamination, the wound heals smoothly, and the anus is dilated to the proper size. A few weeks after surgery, all patients are instructed to start dilation to ensure that the new anus is large enough for defecation. After the second surgery, the surgeon will choose the time to close the fistula, mostly after 2-3 months, depending on the situation. The fistula will be closed and stool will be passed through the anus. In the early postoperative period, stools may be more frequent, and diaper rash and perianal skin erosions should be noted. After a few weeks, the number of stools decreases and the stools become dry. At this point, anal dilation should still be maintained for several months. Some infants may become constipated after surgery and may require increased dietary fiber intake and sometimes the use of laxatives under medical supervision. In children with severe constipation, even standardized use of laxatives, enemas, and training are required. Defecation training for anorectal malformations Defecation training usually begins around age 3. Children with anorectal malformations acquire bowel control later than normal children, and some types of lesions may prevent them from having good bowel control. Long-term outcomes in children with anorectal malformations Children with recto-perineal fistulas generally achieve good stool control. In more complex malformations, children may require long-term treatment or instruction to control bowel movements or prevent constipation, and these patients should be reviewed frequently at the clinic.