Welcome to JA and thanks for this question. Im sorry to hear about your symptoms. Well since you did have a colonoscopy it is less likely that this is due to something serious however it can be something which can cause this sort of bleeding. The first one is definitely hemorrhoids, hemorrhoids can bleed a lot if grow larger in size as they are basically dilated veins in the anus which can bleed at any time and given the amount of bleeding that you are having i think they may have grown in size. And if they have, then you will need interventions to remove them. This can involve surgery to remove the hemorrhoids or even other procedures like banding, laser photocoagulation or sclerotherapy. This will stop the bleeding and solve the problem. As far as your second question is concerned, no hemorrhoids are not hereditary but they can develop in a family because of the dietary issues and other environmental factors but so far they have not been shown to be completely hereditary, they do have a genetic component but they have a multifactorial causation.
APart from hemorrhoids, this can also be an infection inside the intestinal tract which is causing the bleeding, this could also result in diarrhea, abdominal pain and discharge of mucus from the rectum. If this is the case then testing and antibiotics should be able to solve the problem.
But my suggestion is that you have this evaluated ASAP, simply because losing this much blood is dangerous and can lead to fatigue, dizziness, lightheadedness, shortness of breath among various other issues. SO you should get this evaluated ASAP by visiting your doctor and if you have the other symptoms then go to the ER.
Do you have any more questions?
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