someone correct me if im wrong but i thought coffee ground looking vomit was always a sign of a severe bleeding ulcer somewhere in the gastrointestinal tract? if you developed a tear in your rectum i assume you'd bleed red blood. feces turn black due to the presence of red blood cells that have been in the intestines long enough to be broken down by digestive enzymes, and is typically due to bleeding in the upper digestive tract. my father had the same symptoms as you, black chunky vomit, black bowel movements that had a nasty iron smell to it. he ended up having to go through a couple surgery's to try and stop the bleeding. definitely go back to the hospital if you continue to vomit black or have black bowels. you may be in need of a blood transfusion if the bleeding does not stop.