Unfortunately, a biopsy is the best way to diagnose IBD - you can look
for a response to low-dose prednisone, but if that doesn't work, you
still don't know what is going on.  If it does work, well you still don't
really know what is going on, but you have a rough idea.
 
With kindest regards,
Bruce Williams, DVM
[Posted in FML issue 3755]