A nurse is teaching an older adult client who reports constipation. Which of the following instructions should the nurse include in the teaching?

Choice A reason: Limiting activity can worsen constipation by reducing bowel motility. Physical activity stimulates peristalsis via abdominal muscle movement and increased blood flow, so advising reduced activity is counterproductive and not recommended for managing constipation. Choice B reason: While hydration is important, four to five glasses of water daily may be insufficient for older adults, who often need 6-8 glasses (1.5-2 liters) to soften stool and promote bowel movements. This instruction is suboptimal compared to dietary fiber. Choice C reason: Raw vegetables are high in insoluble fiber, which adds bulk to stool and stimulates peristalsis, easing constipation. This dietary change directly addresses the issue by promoting regular bowel movements, making it a key teaching point for older adults. Choice D reason: Bearing down hard (Valsalva maneuver) can strain pelvic muscles and increase risks like hemorrhoids or cardiovascular stress, especially in older adults. Gentle defecation with proper positioning is safer, making this instruction inappropriate.