For what it's worth, I've suffered from constipation most of my life and all evidence points to Irritable Bowel Syndrome / Constipation. After seeing a gastroenterologist, I have used both Metamucil and Fleet glycerin suppositories for some years now at age 79 currently. Half the time I have daily success, but sometimes only after two days and always very firm stools (no diarrhea). This remedy may not be recommended by doctors, but it's worth a try for the more typical IBS constipation cases in my opinion after trying many other remedies. My colonoscopies have been negative. One note is that the intestinal tract seems to be closely linked to the brain and emotions etc in some individuals.