I have been receiving chem all this week and I'm taking Morphine Sulfate. I am extrememly constipated inspite of taking Senokot, Milk of Magnesia, Colace. I've increased the water I drink. I've been eating fruits & vegetable nothing is working. I need immediate relief, please help. How long does it take for Magnesium Citrate to work? Does it give you the runs?