Final answer:
GI function during pregnancy is characterized by delayed gastric emptying and increased gastric acid secretion, contributing to conditions such as nausea, constipation, and gastric reflux or heartburn.
Step-by-step explanation:
During pregnancy, the gastrointestinal (GI) function undergoes several changes. One of the most notable changes is delayed gastric emptying, which can contribute to nausea in the early stages and is a factor in pregnancy-related constipation as the pregnancy progresses. Moreover, the increased circulation of pregnancy-related hormones, like estrogen, progesterone, and hCG, can also affect GI function by influencing intestinal peristalsis and sensitivities to odors, further contributing to morning sickness. As the uterus grows, it places upward constrictive pressure on the stomach, which can lead to gastric reflux, or heartburn. Additionally, there's an increase in gastric acid secretion during pregnancy. Therefore, the correct answer to how GI function changes during pregnancy is 'b) Delayed gastric emptying and increased gastric acid secretion'.