American indian soldiers, when needed to get up early early in the morning to attack the enemy, used to drink lots of water before going to bed. Nature's call was good enough to force them out of the bed in the early morning time. You have problem getting up early, use that trick.
i tried that ....its painful. Best way is to get up a little before fajr e.g if its at 430 , get up 4 EVERY DAY . This way it becomes a routine and it dosent bother you. Like in ramazan
Problem is when people try to get up just a few minutes before fajr azan