I have finally got rid of years of my constipation problem. Most obdurate it was.
I tried skipping dinners, drinking glassfuls of water in the morning and various herbal powders but got temporary or incomplete relief from all these.
I recently stopped drinking water stored in plastic bottles.
I store drinking water in earthen pot.
It worked miraculously.
I no longer have the problem of constipation, ineffectual bowel clearing, insufficient urge or incomplete evacuation.