My Doctor Said I Need An Endoscopy Because I Had

My doctor said I need an endoscopy because I had black stools twice. She wants to check for bleeding. I don’t think I need it. I’ve just had several unrelated surgeries and don’t want to have more. Besides, I went because of constipation and diarrhea. Am I wrong to skip this. Will she still treat me for diarrhea and constipation, do you guess, if I ignore her advice?