At approximately day 1

The proximal hindgut is pulled down to form the ascending colon while the descending colon is fixed on the abdominal wall.

Reference

Larsen WJ. 1997. Human Embryology. New York: Churchill Livingstone Inc.

At approximately day 1

Human gastric lipase is expressed. Intrinsic factor (IF, a protein) can be identified at the base of the gastric glands in the pylorus and corpus.

Duration: 27 weeks

Reference [PubMed Link]

Montgomery RK, Mulberg AE, Grand RJ. 1999. Development of the human gastrointestinal tract: twenty years of progress. Gastroenterology 116(3):702-731.