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.

An Anorectal Malformation (ARM) means that your newborn’s anus or rectum hasn’t developed normally. This occurs during pregnancy and can affect the way your baby passes stool. In some cases, the anus may be missing, narrower than normal, or connected to another structure, such as the urethra, vagina, or bladder.

If your baby is born with ARM, a team of pediatric surgeons and neonatal experts will carefully evaluate the condition. This typically involves physical exams and imaging tests (like ultrasound or contrast studies) to determine the exact nature of the malformation.

What happens after diagnosis?

– Surgical correction: Often, surgery is needed to create a proper opening for bowel movements. This may be done in stages, depending on your baby’s health and complexity of the condition.

– Colostomy (in some cases): Sometimes, a temporary colostomy is performed to enable proper waste removal while healing.

– Recovery and follow-up care: After the main surgery, your baby will be closely monitored by the medical team. Some children may need additional procedures or follow-up care to help them achieve normal bowel control and functionality.