Is ER failure to diagnose infection and sepsis medical negligence?

I went to emergency room three times with severe stomach pains. I was treated as a drug seeker and not diagnosed with partial bowel obstruction. Bowel became necrotic and I went to the emergency room and was again treated as drug seeker.  CT scan showed possible bowel obstruction and I was sent home after given strong pain meds. When the pain medication wore off I drove myself back to emergency room and they called me disgusting and stated that I really wasn't in pain.  I collapsed in the ER before they finally determined I had sepsis. I was with an hour of death according to the surgeon.

I ended up having half of my intestines removed. Had I been properly diagnosed I would have needed only a laparoscopy and had an adhesion removed. Can I file a medical malpractice lawsuit for the hospitals failure to diagnose me and treat me correctly?