In infants, anal stenosis is usually found at 7 to 8 months of age, with signs of incomplete bowel obstruction such as bloating, abdominal pain and vomiting. A small number of infants are born with congenital anal atresia, where no faeces are expelled after birth, and then gradually present with low-level bowel obstruction such as abdominal distention, abdominal pain and vomiting, with no normal opening at the anus.