Vomiting - colonoscpy

My 6-year old Rodney started vomiting a few weeks ago.  For one week, it was off and on until I finally took him to the vet.  They took x-rays and put him on antibiotics.  The x-rays did not show anything and the antibiotics seemed to help.  Once the antibiotics were used, he started vomiting again.  They did a bunch of blood tests and an ultrasound.  All blood test were normal.  The ultrasound showed some thickened intestinal walls and enlarged abdominal lymph nodes. 

Since they still cannot determine whether this IBD or cancer, they not want to do a colonoscopy/endoscopy for over $2,000.

I am tempted to just have them try steroids and change his diet.  He has been well for a few days now; he just seems calmer than usual - but then I am also watching him much more careful than usual.

Any thoughts?  I cannot get a grip on this being cancer when his blood tests are all splendid.

I think most if not all of us here with IBD kitties were given the same choice.  I didn't get the biopsy done.  One thing you should be aware of though for a biopsy to have accurate results your kitty will have to be off steroids for several weeks.  The steroid suppresses the inflammatory cells that they look at from a biopsy.

What did you do?  Is your cat stil alive or did you have to put him down?  How was he/she treated?

He's still here.  He is on a small daily maintenance dose of a steroid for 3 1/2 years and he has done well.