Imperforate anus refers to a birth defect that prevents stool from passing out of the rectum. To repair high anomaly or severe imperforate anus defects, two surgeries are usually required. First, a colostomy is carried out. An opening called stoma is created in the skin and muscle of the wall of the abdomen. The surgeon attaches the end of the large intestine to the opening, and stool drains into a bag attached to the abdomen. The baby is usually allowed to grow for three to six months, and then a second surgery is done to move the colon to a new position. The surgeon makes an incision in the anal area and pulls the rectal pouch down into place, creating an anal opening.