Final answer:
Aging leads to atrophy of the small intestine mucosa, among other changes in the gastrointestinal system, which contributes to maldigestion and malabsorption.
Step-by-step explanation:
An example of a change in gastrointestinal physiology that occurs with aging is b. Atrophy of the small intestine mucosa. Aging can affect various aspects of the digestive system, causing physical and functional changes. Reduced strength and tone of the muscular tissue in the alimentary canal can result in slower movement of food, leading to issues like constipation, while neurosensory feedback is also dampened. The small intestine mucosa may atrophy, which can contribute to problems such as maldigestion and malabsorption. Furthermore, the deterioration of accessory organs function affects their ability to deliver enzymes and bile, which are essential for digestion.