Yep, that's the joys of a grown-up rabbit. They don't all react the same way, some of mine didn't change at all when they hit puberty while others were nightmares. You're lucky if it's only poos, though, one of mine was spraying urine everywhere (he began doing it around 3 and a half month and it went surprisingly high on the walls!). It stopped the day of the neutering - I could have married my vet, really XD. I knew of a female rabbit who was free range and she was pretty clean just... when people sat down, especially at dinner time, she came running and spraying urine on the legs of all the people sitting. Yeah... rabbits. Spaying is your only chance of salvation (it worked for mine, everytime, and the result was pretty much instantaneous in the clean department).