What Causes Abdominal Cramps And Bloody Diarrhea?

I was taking small dose of Pepto-Bismol (1 per day) as a preventative for travelers diarrhea while I was in Egypt for two weeks. I never had any trouble. I stopped two days after I returned. Two days later I began to have ground glass abdominal cramps with occasional bloody diarrhea. By two days later (Saturday) it seemed to be getting better, but this morning I had bloody diarrhea again. Could this be a reaction to using or stopping Pepto-BIsmol? I have a rather delicate intestinal system, with non-celiac gluten sensitivity and dairy sensitivity, both of which cause diarrhea, but was able to meet my dietary needs on my trip. On the other hand, could it be an Egyptian bug that the Pepto-Bismol was holding off and came out when I stopped it?