Every morning drink several glass of warm water (if you don't mind, make it more hot, the reaction will be faster from my experience) until you feel you really get very full. Then, you should have feeling of going to washroom. (Someone may add a few drop of lemon juice, but mostly, the above is enough to get it works.)
Or you can drink papaya juice or eat papaya, then you can go to washroom the next morning.
Because I am not sure how long you don't did it. So, maybe if you can't get the result in the first day. Try 1-2 days more.
In the daytime, drink more water instead of drinking other types of drink. Eat more vegetables and fruits. (Like every one telling the same but it is true.)