I woke up with a huge bruise on left side of stomach. It doesn t hurt and I don t remember hurting myself. I also underwent an endoscopy and colonoscopy because my stomach is extremely sensitive. I have constant bowel movements. The did 3 biopsies. But everything came up fine. So now with this unexplained bruise on my stomach , I m kind of nervous. Is this anything I should be concern about. I don t have stomach pain but I do have a lot of avid reflux.