Definition of Anal Atresia Anal atresia is a condition that a baby is born with. It is a problem with the development of the anus and the part of the intestine leading to the anus. Anal atresia can make it difficult or impossible for the child to pass stool. Causes Anal atresia or imperforate anus can be caused by: The breakdown of the upper gastrointestinal tract by rectal area, so the baby is born without anus. Disruption of organogenesis in the womb. Associated with down syndrome. The failure of growth in the womb when the baby was 12 weeks / 3 months. The disruption or cessation of embryological development in the intestine, rectum and distal parts of the urogenital tract, which occurs between the fourth to sixth week of gestation. Congenital abnormalities of the anus caused by impaired embryonic and fetal growth are influenced by many factors such as genetic factors, chromosomal factors, mechanical factors, hormonal factors, drug factors, radiation factors, nutrit...