I just remembered this thread, and my post above was probably thinking of multiple therapy (eg combining with azathioprine or methotrexate), rather than straight Humira. After chatting to the RAH IBD nurses recently I've been told the protocol is 6 monthly once stable on Humira, but of course if there are concerns always encourage people to contact them immediately, and they'll organise tests etc, but I'm sure they'd want to do a few tests shortly after starting it too.