What Causes Nausea, Urgent Green Fuzzy-smelling Stools, Bad Gas, And IBS?

I have been nauseated, feeling like I will throw up, but don t, and my need to poop is fast. When I go it s green, smells really bad and it looks fuzzy. I have horrible gas also. I have been diagnosed with IBS years ago so I struggle with constipation and belly pain but not usually nausea.