What Are The Side Effects Of Metformin And Avandia?

I am a 67 yr old male. Diabetic taking metformin and avandia. I have had an upset stomach for about three weeks now and have passed a lot of gas orally. If you open your right hand and place it just under you rib cage on you side with the thumb to the back then the spot where the thumb touches your abdomen towards the back is very tender. Twice in the last two weeks it got so sore I could hardly move and the first time I took two tylenol three with codeine to relieve the pain. Just tonight I went to the washroom to urinate and expelled a massive amount of blood. I have an appt nwith an internist this week for a different problem but I would greatly value your opinion now. Thank you
sincerely
Court Johnson