I eat a high fibre diet and take Laxido which helps but it still makes it very difficult to get started.
My solution, is anal/rectal irrigation using a bidet shower head (Enema). The tap and fittings can be purchased on ebay
Push the shower head against your anus and squirt some water in The lubricating effect is immediate, hardly any pushing. Do not squirt too much water in or you may stretch the rectal muscles in the long run.
The biggest cost is the plumber
if you are away from home buy an anal irrigation kit (it Enema kit)
Let me know if it works for you