Soohie and kms0387,
It is possible to have an Inflammatory Bowel Disease such as Crohn's or UC and have celiac disease or gluten sensitivity. All three conditions share many of the same symptoms; however they are all diagnosed differently.
This is a link that describes Celiac disease and how it can be diagnosed:
http://www.celiaccentral.org/Celiac-Disease/21/
If you scroll down the left side of the page you will also find info about Gluten Sensitivity.
One important thing to note is that if celiac disease is suspected, it is important to continue to eat gluten until testing is completed; otherwise, the damage done to the villi in the small intestine may heal and the result will be a false negative and, if you continue to eat gluten you could become very ill, including developing intestinal lymphoma.
At the moment there is no testing for gluten intolerance--it is a diagnosis of exclusion, meaning that after testing for diseases with known pathology like IBD and celiac disease and after becoming symptom-free on a gluten-free diet, the diagnosis of gluten sensitivity can be made.
it is important to note that a person can test negative for celiac disease and then years later test positive.
I follow a gluten-free diet after having used formula to induce remission of my IBD, followed by an elimination or exclusion diet. I tested negative for celiac years before, and the test was repeated when I was really ill, but I had not been eating any food and therefore no gluten at that time.So, I am not certain if I have celiac disease in addition to IBD, or just gluten sensitivity; however, I maintain a strict GF diet, so it no longer matters which it is as the treatment is the same.
I am otherwise digestively symptom-free, so I know when I have been 'glutened'--within 24-48 hours I develop cramping, diarrhea, swollen lymph nodes around my joints, swollen fingers, swollen shins and I get very mentally foggy, especially with math skills, spatial skills (like parking the car!), memory and word finding skills. It now takes 36-72 hours to recover when it used to take me three weeks.
Last comment--there are many hidden sources of gluten--for celiacs even 'a little bit' can cause damage to the small intestine. For those with gluten sensitivity, the amount a person can tolerate depends on their symptoms. I prepare most of my own meals in my own gluten-free kitchen, so I don't have to worry about cross-contamination with gluten in toasters, on bread boards, in colanders, in the jam, the pasta water, etc. I have the most trouble when I try to eat out.
May you have much luck in deciding if gluten is a problem for you.