looking at your age, constipation
is a common problem in geriatric people cz of reduced muscle tonicity. Isapgol is fiber supplementation.
My advice will be have min. 2 bowls of green raw-salad / leafy veg everyday. Drink min 2-3 lit of water supplemented with may be 25min. walk . continue Naturolax granules with water.
Do inform me results , if not working we can make further changes.