Hi johnt, here's some youtube videos that show yoga, massage, etc. to help prevent/relieve constipation. I tried doing the exercises that I could along with simultaneously taking a laxative so can't say for sure the exercises did the job or the laxative but I did have a BM an hour or 2 after doing the exercises. Good luck. Of course do this stuff at your own risk and don't overdo the massages.
I assume amazon has books on constipation which recommend specific stretching/massages.
Fwiw, I think just laying on my back and just pulling my legs back and every which way helped the most. There are a zillion videos


Yoga for Constipation - YouTube
Massage for Constipation - YouTube
Yoga That Helps You Poop with Sarah Badorine - YouTube
Constipation Pooping Positions - YouTube

The bowel movement beet test: How to measure your digestive ‘transit time’ - National | Globalnews.ca

http://movementdisorders.ufhealth.or...-constipation/

https://www.squattypotty.com/shop/ca...toilet-stools/