Anorectal malformations appear differently in boys and girls. In boys, the terminal part of the digestive tract may open into the urethra near the prostate forming a recto-prostatic fistula, or into the bulbar urethra forming a recto-bulbar fistula. These fistulae are very narrow and cannot expel stool. Sometimes these boys may expel a tiny drop of meconium (the baby’s very first stool) at the urethra, or they may pass urine mixed with meconium (meconuria). Sometimes the malformation can occur at a higher level, and the digestive tract can open into the urinary bladder at its neck. This is called a bladder neck fistula. These malformations can be challenging to treat as the bladder neck plays an important role in urinary continence. Still another type of anorectal malformation results in the digestive tract ending in a blind pouch with no communication to any other part. Alternatively, the digestive tract can open on the perineum through a small, abnormal aperture called a perineal fistula. Finally, the anus and the rectum may develop to reach the usual anal site, but they may be too narrow (anorectal stenosis) or blocked somewhere along their length (rectal atresia). A baby boy with anorectal malformation. There is no anus where one would expect to see it. The anatomy of a rectourethral fistula type of ARM in boys. The fistula is the site where the rectum opens into the urethra. The anal pit is where the rectum would have formed the anus normally. In girls, the most common anorectal malformation is a vestibular fistula. In this type of malformation, the digestive tract ends in a tiny, abnormal fistula that opens just behind the vagina, sharing a wall with it. Perineal fistulas, blind-ending malformations with no fistula, anorectal stenosis, and rectal atresia may also occur in girls as they do in boys. The anatomy of a vestibular fistula type of anorectal malformation in girls. The rectum opens through a fistula just behind the vagina instead of passing through the sphincter muscle complex to form a normal anus. A complex anomaly that occurs in girls is the cloaca. In this malformation, the digestive tract, the urinary tract and the reproductive tract open into a single common channel. Such children have a single opening in their perineum for meconium, urine, and mucus from the uterine tract to exit. Cloaca is very commonly associated with malformations of the lower urinary tract, vagina, and uterus. Identifying the type of anorectal malformation is important to plan surgical repair. The pediatric surgeon orders a series of tests to determine the type of malformation. In many cases, the exact anatomy of the malformation is determined just before or as a part of reconstructive surgery.

At least 50% of children born with an ARM have some associated congenital condition. The most common systems to be affected in these children are the urinary system (kidneys, ureters, and bladder), the heart, the spine, and the food pipe. A number of children also have limb deformities. All babies found to have an ARM are screened for these conditions and treated accordingly. Some of the common conditions are Vesicoureteral reflux (urinary system) Ventricular Septal Defect (heart) Hemivertebrae (spine) Tracheoesophageal fistula and esophageal atresia (food pipe). This association of anomalies is often called VACTERL association or VACTERL Syndrome, wherein VACTERL stands for Vertebral, Anorectal, Cardiac, Tracheo-Esophageal, Renal, and Limb. A child is said to have the syndrome if at least three of these defects are present together.

Anorectal malformations appear differently in boys and girls. In boys, the terminal part of the digestive tract may open into the urethra near the prostate forming a recto-prostatic fistula, or into the bulbar urethra forming a recto-bulbar fistula. These fistulae are very narrow and cannot expel stool. Sometimes these boys may expel a tiny drop of meconium (the baby’s very first stool) at the urethra, or they may pass urine mixed with meconium (meconuria). Sometimes the malformation can occur at a higher level, and the digestive tract can open into the urinary bladder at its neck. This is called a bladder neck fistula. These malformations can be challenging to treat as the bladder neck plays an important role in urinary continence. Still another type of anorectal malformation results in the digestive tract ending in a blind pouch with no communication to any other part. Alternatively, the digestive tract can open on the perineum through a small, abnormal aperture called a perineal fistula. Finally, the anus and the rectum may develop to reach the usual anal site, but they may be too narrow (anorectal stenosis) or blocked somewhere along their length (rectal atresia). A baby boy with anorectal malformation. There is no anus where one would expect to see it. The anatomy of a rectourethral fistula type of ARM in boys. The fistula is the site where the rectum opens into the urethra. The anal pit is where the rectum would have formed the anus normally. In girls, the most common anorectal malformation is a vestibular fistula. In this type of malformation, the digestive tract ends in a tiny, abnormal fistula that opens just behind the vagina, sharing a wall with it. Perineal fistulas, blind-ending malformations with no fistula, anorectal stenosis, and rectal atresia may also occur in girls as they do in boys. The anatomy of a vestibular fistula type of anorectal malformation in girls. The rectum opens through a fistula just behind the vagina instead of passing through the sphincter muscle complex to form a normal anus. A complex anomaly that occurs in girls is the cloaca. In this malformation, the digestive tract, the urinary tract and the reproductive tract open into a single common channel. Such children have a single opening in their perineum for meconium, urine, and mucus from the uterine tract to exit. Cloaca is very commonly associated with malformations of the lower urinary tract, vagina, and uterus. Identifying the type of anorectal malformation is important to plan surgical repair. The pediatric surgeon orders a series of tests to determine the type of malformation. In many cases, the exact anatomy of the malformation is determined just before or as a part of reconstructive surgery. Can there be other conditions in the baby along with Anorectal malformations (ARM)? At least 50% of children born with an ARM have some associated congenital condition. The most common systems to be affected in these children are the urinary system (kidneys, ureters, and bladder), the heart, the spine, and the food pipe. A number of children also have limb deformities. All babies found to have an ARM are screened for these conditions and treated accordingly. Some of the common conditions are Vesicoureteral reflux (urinary system) Ventricular Septal Defect (heart) Hemivertebrae (spine) Tracheoesophageal fistula and esophageal atresia (food pipe). This association of anomalies is often called VACTERL association or VACTERL Syndrome, wherein VACTERL stands for Vertebral, Anorectal, Cardiac, Tracheo-Esophageal, Renal, and Limb. A child is said to have the syndrome if at least three of these defects are present together. What happens if my newborn baby has an ARM ( anorectal malformation)? Most of the time, the pediatrician attending the delivery will examine the baby to rule out any anorectal malformation. If your baby is found to have an anorectal malformation, you will be instructed not to feed the baby until the pediatric surgeon has seen the child. Rarely, the condition may come to the attention of the parents first. In either case, a pediatric surgeon needs to be called in at the earliest. The pediatric surgeon will examine the baby physically and order X-rays. He or she will also look for associated anomalies, especially esophageal atresia as it needs immediate attention. The immediate priority is to create an outlet for the pent-up intestinal contents, failing which the intestines could rupture leading to a life-threatening situation.

Findings from the physical exam and the X-rays will help the surgeon decide on one of the following:

a) Immediate corrective surgery- This is possible in certain types of malformations where the digestive tract has developed almost all the way to the anus. The surgeon will perform the surgery when the baby is at least 24 hours old. An anus is created at its normal position.

b) Delayed corrective surgery- in malformations such as vestibular fistulae or perineal fistulae, the opening may be big enough to allow the baby’s meconium and first milk stool to pass easily, but too small for formed stool. In such a case, the operation can be deferred till the baby gains some weight. Daily gentle dilation of the fistula with a feeding tube may be required till the operation.

c) Colostomy construction followed by delayed corrective surgery- this plan of action is followed in boys with rectoprostatic or retrobulbar fistula or blind pouches and in girls with cloaca or blind pouches.

Boys and girls with rectal atresia also need this line of treatment. First, the surgeon creates a colostomy which is an opening of the large intestine onto the abdominal wall. The baby’s meconium and stool are expelled through this opening and collected in a colostomy bag. This temporary outlet for intestinal waste and stool is created so that the baby can feed and grow. When the baby has gained sufficient weight, corrective surgery is performed. A third surgery is then needed to close the colostomy.