Floyd2019, has he ever been tried on a dewormer? Sometimes irregularities in a rabbits droppings can be due to an intestinal parasite. Even if a fecal float were to come back negative, there can still be a worm load that needs treating. I would try fenbendazole, 20mg/kg once a day for 5 days, then 10 days off, then one more dose. I've known of other rabbit owners that have had persistent unexplained health and poop issues with their rabbits, and had it clear up after giving a dewormer. So something to consider. I'm including a link on pinworms, but it won't necessarily be pinworms that could be affecting your rabbit. It's just the most common intestinal parasite for rabbits to get.
http://www.medirabbit.com/EN/GI_diseases/Parasitic_diseases/Pass/Pass_en.htm
@EricaWD has your vet done a thorough dental exam to rule that out as the possible cause for your rabbit not eating hay? Dental problems causing mouth sores is the most common health cause of a rabbit not wanting to eat hay but being willing to eat other foods like pellets and veggies.
