Hello and welcome. If the presentation was acute, it can be related to an infection like amoebic dysentery, and will require antibiotic coverage. But if you have had similar symptoms in the past, intermittently then you will undoubtedly require a colonoscopy at the earliest. I would either way recommend a blood profile and stool analysis to check on and either confirm or rule out an infection. If an infection is ruled out, we need to look for conditions like irritable bowel syndrome, diverticulosis, etc. Please visit a doctor at your earliest convenience as tou have begun to lose blood and this is not healthy. Best wishes.