What Causes Blood In Stool Of A Diabetic While On Anacin?

hello, well I am having lower back problems with L 4 and 5 and also degenerative spine. the pain is tolerable in the morning, but after work I get totally helpless. But my pain is getting worse during the day so I have been taking anacin two tablets some times another two, I try to stay off any pain meds during the weekends and on my time off. plus I have type 2 diabetes and i have been noticing blood in my stools, could i be taking the wrong pain meds?