What is an imperforate anus?
An imperforate anus is a birth defect in which anus is opening of the anus is absent or blocked. This happens while your baby is still growing in the uterus. This defect means that your baby has an inappropriately 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 is more common in boys than in girls. The rectum, bladder, and vagina of a female baby with an imperforate anus sometimes have common large opening. This opening is known as cloaca.
The condition develops in the uterus during the fifth to seventh weeks of pregnancy. The cause is not clear. Many times babies with this condition also have other defects of the rectum.
Doctors generally can diagnose this condition some times after birth. This is a very serious condition that needs immediate treatment. In most of the cases, surgery is needed to repair the defect. The aspect following surgery is very positive.
What are the symptoms of an imperforate anus?
The signs of imperforate anus are generally clear 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 inaccurate 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 defects. Some of these may be:
- kidney and urinary tract defects
- defects of the spine
- windpipe, or tracheal, defects
- esophageal abnormalities
- defects of the arms and legs
- Down syndrome, which is a chromosomal condition having cognitive delay, mental disability, a characteristic facial appearance, and weak muscle tone
- Hirschsprung’s disease, which is a condition involving absence of nerve cells of the large intestine causing problems with passing stools
- duodenal atresia, which is absence or complete closure of the first part of the small bowel
- congenital heart defects
How is an imperforate anus diagnosed?
A doctor can often diagnose an imperforate anus by performing a physical exam after birth. An X-ray of the abdomen and abdominal ultrasound can help affirm the level of the abnormalities.
After diagnosing imperforate anus, your baby’s doctor should also test for other abnormalities related to this condition. Following tests can be performed :
- X-rays of the spine to recognize bone abnormalities
- spinal ultrasound checking for abnormalities in the vertebral body, or bones of the spine
- echocardiogram looking for heart anomalies
- MRI looking for evidence of esophageal abnormalities such as formation of fistulae with the trachea, or windpipe
What are the treatments for an imperforate anus?
This condition almost always needs surgery. Multiple procedures are sometimes essential to correct the problem. A transient colostomy can also allow your baby time to grow before surgery.
For a colostomy, your baby’s surgeon makes 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 rhat recieves waste products.
The type of corrective surgery required will depend on the specifics of the defect, such as how far your baby’s rectum descends, how it affects the muscles around it and whether fistulas are involved.
In a perineal anoplasty, your baby’s surgeon closes any fistulas so that attachment of the rectum to urethra or vagina closes. They then make an anus with normal positioning.
A pull-through operation is when your baby’s surgeon pulls the rectum down and attaches it to the new anus.
To prevent the narrowing of the anus, it may be necessary to stretch the anus regularly. This is called anal dilation. You may need to repeat this periodically for a few months. Your doctor can teach you how to do this at home.
What is the long-term outlook?
Your doctor will direct you on how to do anal dilations. These confirm that the anal opening is large enough that stool can pass through it.
Some children will face problems with constipation. Toilet training may take a little longer time. Stool softeners, enemas, or laxatives may be required to ease constipation later in life. Surgery can often fix the abnormalities, and most children do very well.
A diet rich in fiber and regular follow-up care throughout childhood are helpful.
- Anorectal malformation. (n.d.).pedsurg.ucsf.edu/conditions–procedures/anorectal-malformation.aspx
- Imperforate anus. (2013).cincinnatichildrens.org/health/i/imperforate-anus
- Imperforate anus and anorectal malformations. (n.d.).seattlechildrens.org/medical-conditions/digestive-gastrointestinal-conditions/imperforate-anus