I think the drugs do have their place really if you have tried other non drug options and they have failed. Its clear you are not taking any drug that leads to constipation
. You might try to walk, get some exercise, drink much water and fluids, eat much vegetables and fibre diet and regularize your eating periods/.
This could really be of help. Other wise, above 50 years of age, constipation usually warrants a colonoscopy
and a hemocult to exclude a colonic pathology that could be causing the cosntipation.
I believe its worth discusiing doing these tests too with your physician as you associate those life habits I proposed to your drugs.