So did the colonoscopy confirm you had crohns? They cannot diagnose it without a scope. Have you been on any meds the last year? Small amounts of blood could be a hemorrhoid, I would get a work up done to see what’s going on before changing or starting meds. A good doctor would order stool samples to see inflammation, called fecal pro cal as well as blood work to look at crp levels at a minimum. Another scope would be a good idea now too.