Information on Imperforate Anus

Imperforate anus is congenital defect in which the opening to the anus is missing or blocked. The anus is the opening to the rectum through which stools leave the body. Imperforate anus occurs in about one of every 5,000 newborns. It is somewhat more common in boys than girls. 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 link 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. A low lesion, in which the colon remains close to the skin. In this case, there may be a stenosis (narrowing) of the anus, or the anus may be missing altogether, with the rectum ending in a blind pouch. A high lesion, in which the colon is higher up in the pelvis and there is a fistula connecting the rectum and the bladder, urethra or the vagina.

A persistent cloaca , in which the rectum, vagina and colon are joined into a single channel. Imperforate anus is generally there along with other birth defects spinal problems, heart problems, tracheoesophageal fistula, esophageal atresia, renal anomalies, and limb anomalies are among the possibilities. Imperforate anus usually requires immediate surgery to open a passage for faeces. Surgery depends on the type of imperforate anus blemish. For a high-type imperforate anus defect, the surgery usually creates a temporary opening for the colon in the abdomen. This is called a colostomy.

The infant is allowed to develop for several months before more intricate repairs are attempted. Surgery for a low-type imperforate anus includes closing any little tube-like openings (fistulas), creating an anal opening, and putting the rectal pouch into the anal opening. For other related anal repairs, the surgery makes a cut in the abdomen and loosens the colon from nearby structures. This allows the colon to be re-positioned. A cut in the anal area is made to pull the rectal pouch down into place and create an anal opening. A colostomy may be closed during this procedure, or may be left in place for a few more months and closed at a later stage.