Digestion is an amazing and complicated process. If eaten separately, carbs travel through the fastest, then protein, then fat travels the slowest. But if eaten together, they all travel slower. I think it is very individual. In my experience and observation, 24 to 72 hours is way too long. It happens in a much shorter time for me.
When I worked in the nursing home, the nursing assistants would count the hours after the cornbread and beans and spinach meal and could determine when they would be very busy
. It was around 18 hours after the meal.