Loose, disintegrating stool with odd smell

I have been having abdominal pain and nausea for about three weeks now. Additionally, I've lost about 18 lbs in the past month, unintentionally. I saw a GI specialist who I will be following up with, but since then I've had unusual stool. It comes out loose, but solid, and after a few seconds it starts to disintegrate and separate in the bowl. It also has a very unusual smell. It doesn't smell like stool at all, it's hard to describe but it's almost metallic like in odor. Any ideas on what this could be?