Having enumerated all the possible explanations for my sleepiness and bloating I decided to test out the possibility that it was due to my coming off steroids. I put myself back on 4mg of dexamethasone. My tiredness has left me and the bloating has been much better. In fact I have probably overeaten today since my son and his family was with us and we ate at a restaurant.
Now I must find a way of living with the bigger dose of steroids.