Helen G. For my mother's chronic constipation or family doctor suggested vit. C. I began giving her two grams the first day. Didn't do a thing. The next day went to three grams. No effect. Then upped the dose, spread out through the day until finally at 6 grams she had an unassisted bowel movement. Each person is different and according to Linus Pauling your bowels will tell you when you are receiving your optimum dose. Vit. C has been wonderful. Who needs constipation on top of all the other PD side effects. Carol Brow