Luckily the problem has stopped from my knowledge. He doesn’t seem to be having any more problems at all other than wanting to hide and he grunts at me if I open his cage while he’s sleep. I also took him to the vet and they said he looked fine. I think at the time it was because of the different pellets he was eating and the lack of veggies because I was brand newTimothy Complete is what all my bunnies have eaten. First one, I don't know how old he was when he died as we rescued from a breeder, 2nd one is 12 and the 3rd one is over 6. I think that brand is a good value for the nutrition it provides. The plain kind is best, no fruit added. Good choice. Orchard grass is what mine like the best as far a hay is concerned. Some bunnies seem to get excess cecals if too much fresh vegetables or fruit, other seem to tolerate with no problem Hopefully yours is the latter. As they age, the digestion changes and greens might need to be adjusted.