Sorry to hear your added troubles, you sure didn't need them right now.
I was out on disability, with disability insurance coverage, for 4 months due to cdiff (well, 6 wks for the surgery, the rest for cdiff) and could have stayed out longer if I'd still been in the horrendous pain I was in; and I'm not in the medical field. I had such terrible abdominal pain I couldn't even wear clothes except very loose fitting sweat pants and couldn't stand upright more than 20 mins. or so or the pain got much worse.
Your doctor is wrong, he can keep you out if you're sick enough or in pain enough. The disability insur. rep. may have to go to the supervisors who meet with a kind of 'diagnosis board', a kind of medical review board, within the group (I don't know the technical name of the group that meets to decide on difficult cases) and they may require follow-ups every 2 weeks (that was what and how they did in my case). My case worker for the insurance knew very little about the disease but the physicians on the review board did. There weren't specific instructions or "set" time off for it either, that's why I had to do the follow-up every 2 weeks (and she went to the review board every 2 weeks). She did tell me they'd had only 1 or 2 other cases (my dis. insur. co. was a major carrier out of Dallas TX - PM me if you want to know the name).
As weak, and pained, and sick as we are - we have to fight all these battles ourselves. That's one thing that makes this disease so much more terrible than it needs to be......
Hang in there - and fight for your rights. You DO have rights, but sometimes they are hard won.