Suggest Treatment For Painful Bowel Movement

I have had strep throat (without knowing it) for about 10 days. I just received Amoxicillin 500MG. Took two pills. Just had a bowel movement. The stool was very sharp and felt like it was slicing me. I have had this problem before and it caused some bleeding. I had blood also this time. Bright red, not pouring out, but on the first clean, covered most of the paper. The more I cleaned, the less blood. If I wasn t taking Amoxicillin, I would just put it down as a sharp stool causing a small cut (have had this a few times). What are the odds that it is the Amoxicillin after two pills (bowel movement 1 hour after second pill). As far as I know, not allergic