There's actually a good reason the greens are causing constipation: because greens are so alkalizing, they help the body release acids into the colon for elimination.
However, acids are also thick and sticky, and they tend to gum up our "pipes" -- so you can choose your preferred method for staying clear while you're increasing your greens intake:
` more fiber
` more good flora
` more magnesium
` more Vitamin C
` occasional enemas & colonics (when other means don't work)
Also, be sure to keep your intake of oils high, and use clay occasionally to absorb the toxins/acids as they are released.