Try to drink a liter of water per 40 lbs of body weight, and try to shift your eating to more alkaline.
A good way to remove constipation naturally is to use vegetable smoothies ... here is my recipe:
a couple of handfuls of organic baby spinach
5 or so florets of organic broccoli
a stalk of organic celery
an organic carrot
a handful of seeds (flax, sunflower and/or pumpkin)
1/2 grapefruit, organic if possible
Add a liter of pure water, preferably alkalized.
blend these, or some other veggie recipe, and drink one in the morning. I sometimes even drink more during the day.
Also, you can use cascara sagrada, or a cascara sagrada blend ... you can get this from your health food store - should run around $7 for a bottle. The cascara is a temporary solution, to use while you are detoxing, cleansing.