How long between the NPO and the pred? It's possible the effects of the NPO just lasted a little while and the bleeding would have come back anyway but was kept away by the 40mg pred. So it could still be from the taper.
Also, how long were you at 40mgs? It's also possible that the pred just hasn't had long enough to fully kick in yet, and the bleeding is just now coming back from the nice effects of the NPO. Unless there was anything else in your life/diet that changed?
For me it sometimes took up to three weeks at 40 mgs for bleeding to stop.
Follow my story: ronnielee-fightingforit.blogspot.com
32-year-old single female (teacher)
10/4/12 - proctocolectomy / J-Pouch construction / loop ileostomy
Take-down scheduled December 11th
Dx mild/moderate UC 1995
Dx severe pancolitis 2011