For severe constipation, I found dews bile salts to help with constipation more than anything. It seems to actually help break down fat and stimulate peristalsis. For me it works much better than magnesium, herbal laxatives, high dose vitamin C etc... I take 1 or 2 a week and produces a decent bowel movement every time. You have to play around with how much can be tolerated because too much can irritate the Gi tract or cause diarrhea. I take the bile salts a little while after a meal when the stomach HCL has already done most of its work.