<Li> Developmental, congenital or genetic conditions <Ul> <Li> Duodenal (intestinal) atresia </Li> <Li> Hirschsprung's disease </Li> <Li> Meckel's diverticulum </Li> <Li> Pyloric stenosis </Li> <Li> Pancreas divisum </Li> <Li> Ectopic pancreas </Li> <Li> Enteric duplication cyst </Li> <Li> Situs inversus </Li> <Li> Cystic fibrosis </Li> <Li> Malrotation </Li> <Li> Persistent urachus </Li> <Li> Omphalocele </Li> <Li> Gastroschisis </Li> <Li> Disaccharidase (lactase) deficiencies </Li> <Li> Primary bile acid malabsorption </Li> <Li> Gardner syndrome </Li> <Li> Familial adenomatous polyposis syndrome (FAP) </Li> </Ul> </Li> <Ul> <Li> Duodenal (intestinal) atresia </Li> <Li> Hirschsprung's disease </Li> <Li> Meckel's diverticulum </Li> <Li> Pyloric stenosis </Li> <Li> Pancreas divisum </Li> <Li> Ectopic pancreas </Li> <Li> Enteric duplication cyst </Li> <Li> Situs inversus </Li> <Li> Cystic fibrosis </Li> <Li> Malrotation </Li> <Li> Persistent urachus </Li> <Li> Omphalocele </Li> <Li> Gastroschisis </Li> <Li> Disaccharidase (lactase) deficiencies </Li> <Li> Primary bile acid malabsorption </Li> <Li> Gardner syndrome </Li> <Li> Familial adenomatous polyposis syndrome (FAP) </Li> </Ul> <Li> Duodenal (intestinal) atresia </Li> <Li> Hirschsprung's disease </Li>

Where does most of the digestion occur in the small intestine