Water is what makes your poop move thru the colon. Since you’ve had a long standing issue with it maybe the 8 glasses of fluid a day is what you require? Fructose or fruit sugar pulls water into your colon to help you go too. Yes flax seed does it too but can cause loos stool too. As another reader stated 1 tblspn to start in morning as a test run and increase your fluids. Since you’ve had a long term issue are you seeing a GI doc?