This sounds like caecotrophs to me. Bunnys do two types of poop- normal, round poops that you have described, and caecotrophs, which are like a small cluster of tiny grapes, which are quite mushy.
Rabbits should generally eat these caecals straight from their anus.
Put very briefly, rabbits need to redigest again, the food they have eaten, so the first time they pass a 'poop', they will eat it, and digest it again, to get all the goodness out of it that they weren't able to get before (plant material is hard to digest for many animals).
If your bun isn't eating these caecals then either they could be overweight (so can't reach round to eat them, and they may get stuck to their butt fur), or they have a diet that is too good, and too nutritious. Cutting back the pellets, and really pushig the hay is the solution to this- bunny's diet should be 75-80% hay, and the rest pellets and a variety of veggies.
Jen