You could try posting on the Gastroenterology Community forum and see if anyone can offer advice.
A non invasive test
for inflammation in the GI tract is a Calprotectin Stool Assay test
, which if out of range (norm is around 20, mine can be as high as 40 when I have a flare of my Crohn's) can detect inflammation somewhere, but not specifically, in the GI tract. It is cheap and easy to do and only requires a stool sample.