Hi I Have Chronic Pain Issues From My Time In

hi
I have chronic pain issues from my time in the Marines. I was put on low dose morphine pills for a few months now. I recently had some digestive issues because of them. I took tums max for that and after a couple days I finally was able to break my constipation but my stool is very light tan. I heard that can be a liver issue but I don't think morphine and tums can hurt your liver like that, so is it possible the opiate constipation and tums cause that by any chance? I cant realy ask my VA provider b/c I am out of country atm and just need a quick answer..many thanks