Imperforate anus is a birth defect where the opening to the anus is missing or blocked. The anus, also known as the rectum, is the opening at the end of the intestines through which stool (bowel movement) leaves the body. Imperforate anus may end in a pouch, be too narrow (stenotic or atresic), or open into part of the urinary system, female or male reproductive system, or other system of body Symptoms may include absence of the first stool within 24 to 48 hours after birth, no anal opening, anal opening in an abnormal place, stool coming out from the vagina, base of penis, scrotum, or urethra, and/or swollen belly. Although the exact cause of imperforate anus is not fully understood, it is believed to be due to the abnormal development of the rectum when the embryo is forming inside the womb. Many forms of imperforate anus occur with other birth defects. Imperforate anus may also be part of a syndrome with multiple birth defects. Treatment may include colostomy and surgery to correct the defect. Prognosis depends on the severity and type of imperforate anus and the severity and type of any other birth defects.