Here I will not discuss possible causes, check out with your doctor.
If the problem is not solved by diet changes or other suggestions them probably the best is to use LINSEED=FLAXSEED=PISHTAN which safely can be used for the long term!
Buy the whole seeds and store them in the fridge.
Crush /grind one to two tables spoons of the seed and take this twice a day at least some 40 minutes before food or an hour after food and also not together with supplements you are taking
[so maybe the best time is early morning after waking and before sleep.[or before the evening meal]
You can just add it to a glass of water and after drinking this drink an extra glass of water [if you wish take a teaspoon of honey or maple syrup with it as a sweetener]
This is the BEST long-term “laxative” one can take safely.

It may take 2 to 3 days before it starts working.
If you decide to grind/crush an amount for more than one day of flaxseed then keep the ground powder in the freezer as linseed [flaxseed] spoils very quickly!

If you still have doubt if this is a good thing to do, then Nicole may convince you….