Bush pear comice not producing fruit

Sounds like it needs a pollinator in your garden, as there is not one nearbye. Williams Bon Chretien is a good pollinator for Doyenne du Comice. Then the profuse blossom will be fertilised and the tree should make pears for you. If the set is heavy. and you can reach, thin them out, it can be done at white bud or remove the largest in a set mid June and remove any mishapen ones too. The June drop will do the rest. Unless a pear tree is huge, we had them in our last garden, you have to fuss over them a bit. It is easy to be disapointed with apples and pears, due to pests, pollination, frosts and bearing every other year.