What Causes Vaginal Bleeding And Black Stools After A Hysterectomy?

I had a vaginal hysterectomy 8/26, and felt great for almost 1 week. I ran a 102 deg f temp and had abdominal pain. Took CAT scan and ultra sounds without contrast because of my allergies. They said a hematoma between bladder and intestines.
I was hospitalized for 5 days on 2 strong antibiotics. The meds made me really nausious and migraine headache- I took them until today (7 days) - Now I have some blood tinged discharge vaginally and black stools. Shoud I be concerned?