An older adult who is on bed rest after surgery is prescribed morphine for pain. Which of the following is the nurse's priority for preventive care?

A. Poor solid food intake: While reduced solid food intake can lead to inadequate nutrition, it is not the most urgent concern with morphine use. The immediate complication to anticipate with opioids in an immobile older adult is impaired bowel motility. B. Constipation: Morphine slows gastrointestinal peristalsis by binding to opioid receptors in the gut, significantly increasing the risk of constipation. Older adults on bed rest are particularly vulnerable, and unmanaged constipation may progress to fecal impaction or bowel obstruction, making prevention the priority. C. Poor liquid intake: Decreased fluid intake can worsen constipation and contribute to dehydration. However, the direct effect of morphine on bowel motility presents a greater immediate risk than hydration status alone. D. Diarrhea: Diarrhea is not a typical adverse effect of morphine use. In fact, opioids usually produce the opposite effect by slowing bowel activity, so this is not a priority complication to monitor in this context.