I have the same problem. There is always about
1/4 of the bottle left in. I don't discard the leftover amount. Instead, I save the amount that remains and pour it into the bottle that has 1/4 left. Therefore, I feel I don't waste it.
The best postition for me is to kneel with my butt in the air...not a pretty sight, but I make sure I am by myself in the bedroom while doing this....and stick it in. Try remaining in that position for a few minutes. Then I lie on my side. Sometimes it stays in and sometimes I can only hold it for a short while. I take Canasa suppositories in the mornings. I have better luck retaining them than the cort enemas.