Hello and welcome to Healthcare Magic. Thanks for your query.
Passing blood in feces is a problem which should be taken seriously. There can be a wide variety of causes for this and you need a physical examination and further investigations to make a diagnosis.
cigarettes and marijuana can have a lot of adverse health consequences, including gastritis
and even gastro-intertinal bleeding. I would advise you to refrain from these habits and see a doctor for a detailed evaluation of your problem, so that further treatment can be planned.
Wish you all the best.
Dr. Jonas Sundarakumar