Had Diarrhea For A Few Weeks Stopped Eating Gluten And

Had diarrhea for a few weeks stopped eating gluten and dairy diarrhea went away then I started getting constipated and there was blood in my stool it was either red or maroon. I I have a colonoscopy coming up so I had to start eating gluten again but the diarrhea has not come back so I’m not sure if the gluten was the problem in the first place. And now the blood in my stool seems to be lessening although there are now Black specs in my stool. I recently started having lower back painAnd I don’t understand if that’s related to the rest of the symptoms. I have a family history of colon cancer. I just want to know if these symptoms are connected and what they could possibly be.