Watermelon is fantastic. You can buy an entire watermelon, and spend the day eating it. I would juice one, and drink half a watermelon a day for one week.
Better yet, sit in a warm bath eating it, as much as you can, for as long as you can. Keep going to the bathroom every time you get the urge.
This completely cured my lower back pain.
You can also make a tea out of parsley (organic). Drink this throughout the day.
If you can't find watermelon anymore, get some watermelon seed tea, most likely at any good health food store.