Rheumatoid Arthritis Support Group
Rheumatoid arthritis is a chronic, inflammatory, multisystem, autoimmune disorder. It is a disabling and painful condition which can lead to substantial loss of mobility due to pain and joint destruction. The disease is also systemic in that it often also affects many extra-articular tissues throughout the body including the skin, blood vessels, heart, lungs, and...

But I would check with your doctor.
Also.....use your phone and photograph this should it happen in the future and show to doctor. My veterinarian gets lots of photos of my dog's poo.
Do you get migraines?
Too much to.e between MTX and vomiting, I think, to blame it on the MTX.
[If it was the cancer dose, I'd agree that vomiting can be an issue. But the RA dose is far, far less.]
Pinkcat - it is my understanding that you should ever take prednsione and an aspirin based DMARD or aspirin as they are too hard on the stomacn and GI tract. I can't believe a doctor told you to do that, and sorry you got the results you did!