What is an imperforate anus? An imperforate anus is a birth defect that happens while your baby is still growing in the womb. This defect means that your baby has an improperly developed anus, and therefore can’t pass stool normally from their rectum out of their body. According to the Cincinnati Children’s Hospital, about 1 out of every 5,000 babies has an imperforate anus or other malformation of the anus or rectum. It occurs more often in boys than girls. The rectum, bladder, and vagina of a female baby with an imperforate anus sometimes share one large opening. This opening is called a cloaca. The condition develops in the womb during the fifth to seventh weeks of pregnancy. The cause is unknown. Many times babies with this condition also have other defects of the rectum. Doctors usually can diagnose this condition shortly after birth. This is a very serious condition that requires immediate treatment. Most babies will need surgery to repair the defect. The outlook following surgery is very positive.

What are the symptoms of an imperforate anus? The signs of imperforate anus are usually obvious soon after birth. They include: no anal opening

an anal opening in the wrong place, such as too close to the vagina

no stool in the first 24 to 48 hours of life

stool passing through the wrong place, such as the urethra, vagina, scrotum, or the base of the penis

a swollen abdomen

an abnormal connection, or fistula, between your baby’s rectum and their reproductive system or urinary tract About half of all babies born with imperforate anus have additional abnormalities. Some of these may be: kidney and urinary tract defects

abnormalities of the spine

windpipe, or tracheal, defects

esophageal defects

defects of the arms and legs

Down syndrome, which is a chromosomal condition associated with cognitive delay, intellectual disability, a characteristic facial appearance, and weak muscle tone

Hirschsprung’s disease, which is a condition involving missing nerve cells of the large intestine

duodenal atresia, which is an improper development of the first part of the small bowel

congenital heart defects

How is an imperforate anus diagnosed? A doctor can usually diagnose an imperforate anus by performing a physical exam after birth. An X-ray of the abdomen and abdominal ultrasound can help reveal the extent of the abnormalities. After diagnosing imperforate anus, your baby’s doctor should also test for other abnormalities associated with this condition. Tests used may include: X-rays of the spine to detect bone abnormalities

spinal ultrasound looking for abnormalities in the vertebral body, or bones of the spine

echocardiogram looking for cardiac anomalies

MRI looking for evidence of esophageal defects such as formation of fistulae with the trachea, or windpipe

What are the treatments for an imperforate anus? This condition almost always requires surgery. Multiple procedures are sometimes necessary to correct the problem. A temporary colostomy can also allow your baby time to grow before surgery. For a colostomy, your baby’s surgeon creates two small openings, or stoma, in the abdomen. They attach the lower part of the intestines to one opening and the upper part of the intestines to the other. A pouch attached to the outside of the body catches waste products. The type of corrective surgery needed will depend on the specifics of the defect, such as how far your baby’s rectum descends, how it affects the nearby muscles, and whether fistulas are involved. In a perineal anoplasty, your baby’s surgeon closes any fistulas so that the rectum no longer attaches to the urethra or vagina. They then create an anus with normal positioning. A pull-through operation is when your baby’s surgeon pulls the rectum down and connects it to the new anus. To prevent the anus from narrowing, it may be necessary to stretch the anus periodically. This is called anal dilation. You may need to repeat this periodically for a few months. Your doctor can teach you how to perform this at home.