What Causes Blood In Stool After Having Cocaine?

Hi Dr, i recently started injecting cocaine, i am experiences some signs on my body recently, for ex. my hands are now always very dry,red but not swollen i also had a case of blood in my stool,some was bright red and some dark in colour could be this associated to the drug use? i do rotate injections site staying away from legs,wrists.neck etc... i do use only sterile equipment and i am very clean,