Final answer:
The gastrocolic reflex (option d) is responsible for babies often needing a diaper change after feeding as it increases bowel movement. This reflex is a normal part of the digestive response and is distinct from other conditions like esophageal reflux or allergic reactions. Initial clearing of meconium occurs post-birth, transitioning to regular stools as the baby begins digestion of milk.
Step-by-step explanation:
The reason babies' diapers often need to be changed when they are fed is because of the gastrocolic reflex. This reflex is an instinctive physiological response to the stomach stretching after food enters it. When a baby eats, the gastrocolic reflex triggers peristalsis in the colon, leading to increased bowel movement and the potential for stool passage, hence a dirty diaper. Unlike conditions such as esophageal reflux, which is the backflow of stomach contents into the esophagus, or allergic reactions to food, which involve the immune system, the gastrocolic reflex is a normal and expected digestive response.
It is not typically associated with distress or discomfort unless it leads to excessive bowel movement. Newborn behaviors, such as crying, rooting, and suckling, are related to survival instincts, while the clearing of meconium, a sterile substance accumulated during gestation, marks the initial bowel movements post-birth. This contrasts the subsequent stool changes as the baby starts digesting breast milk or formula.