Anomalies of the postpharyngeal foregut

Oesophageal atresia and tracheo-oesophageal fistula are associated with the development of the lungs. In oesophageal atresia, amniotic liquid cannot be evacuated into the intestinal tract. The result is an accumulation of excess fluid in the amniotic cavity (polyhydramnion).
Oesophageal stenosis typically occurs in the lower third of the oesophagus. A congenital hiatal hernia results when the oesophagus remains short and a part of the stomach protrudes into the thorax.
Infantile pyloric stenosis is characterized by hypertrophy of mainly the circular muscle fibres of the pyloric part of the stomach. Due to this, food can no longer pass the pylorus and the consequence is severe vomiting. Conventional wisdom is that this condition is not a congenital abnormality; it is a functional impairment which appears after birth.
Heterotopic gastric mucosa is when the mucosa of the stomach is found elsewhere in the digestive tract, proximal to the ileocolic junction.