can change of BM caused by omeprazole?

I have constipation most of the time most probably because I don't drink much water, eat vegetable, exercise and hold my BM. A few months ago I noticed a small streak of blood in my stool, and that made panic, but I just thought that it was because of my hard stool. After that  I would see streaks of blood from time to time and accompanied by 2 streaks of mucus. The last blow when I was so constipated that it took me another day to pass the stool, and it was streaked with blood and mucus. I went to see a gastro he checked my anus and said that I ruptured a muscle/vein (?) because my anus stings. I also told him about the gnawing pain in my stomach, not painful but there was a discomfort, and gastric acid that goes up to my  throat. Also, a family history of gastric ulcer. He recommended Omeprazole once a day, stool softener and a cream for my anus for 30 days.  Since, I don't have money to buy all of them, I just bought Omeprazole, and has been taking them for 7 days now. After 2 days of taking it, I had a foul smelling soft stool, with undigested food. Now, for 2 days I have had hard stool, that cause me to strain but not as before, so, I had a blood streak again, smaller amount of mucus but BLACK SPECKS in my stool. Today, I had black specks, and 1/8 of my stool looked black and mushy. everything was hard and compact. Sorry, for the long post, but this is driving me crazy and I can't afford yet to go back to the doctor. I hope someone can help me out on this one. Thank you very much.

[bmbothered]

oh, by the way. My stomach now feels so much better after taking Omeprazole, but I wonder what's happening with my stool. Thanks.