Minimally Invasive Surgery

Imperforate Anus

Signs and Symptoms
Diagnosis
Treatment

Signs and Symptoms

Imperforate anus is a birth defect that occurs in about one of every 5,000 newborns. It is somewhat more common in boys than girls and may include a single abnormality or a combination of abnormalities of the rectum and anus. The rectum is the end of intestine that connects with the anus and the anus is the body's opening to dispel solid waste. Although there is no known cause for this condition, there are many forms of this birth defect, including:

• The absence of an anal opening.
• An anal opening in the wrong position, usually a very small opening.
• An abnormal connection or opening, called a fistula, between the rectum and the urethra, bladder or vagina.
• In girls, the rectum, urethra and vagina can join together to form a single opening. This is called a cloaca and is very rare.

If the anus is missing, there is no outlet to release stool after birth. The intestine ends in a blind pouch, so your infant's stool, called meconium, remains in the intestine. This can cause vomiting and an enlarged or swollen abdomen.

In some cases, the rectum may end high in the pelvis or it can end low, closer to the correct position.

If there is a fistula or connection between the intestine and the bladder, stool may be excreted with urine. If there is a fistula between the intestine and the vagina, stool may pass out of the vagina.

Reviewed by health care specialists at UCSF Children's Hospital.
Last updated January 15, 2008