Final answer:
The nurse should first assess the patient's food and fluid intake (option B) to identify potential dietary causes of constipation and to ensure the individual consumes sufficient fiber and fluids.
Step-by-step explanation:
The initial action a nurse should take when an older adult in an assisted living facility presents with recurrent episodes of constipation is to assess the patient's food and fluid intake. This assessment is crucial because it helps to identify potential dietary causes of constipation and determine if the individual is consuming enough fiber and hydrating fluids, which are essential for bowel regularity. Before considering interventions such as taking stool softeners or fiber supplements, it is important to have a complete understanding of the patient's dietary habits, as increasing the intake of fiber-rich foods like whole grains, vegetables, fruits, and ensuring adequate fluid intake can be effective in relieving constipation.