Yes, the "gold standard" for CD diagnosis is a small bowel biopsy; unfortunately, the tools that they use for that only reach so far down into the small intestine. Some people have damage below that distance.

Some Gastroenterologists are starting to use a camera endoscopy - I believe it is one that you swallow that just passes through. Unfortunately, that won't get them any samples to test for villi erosion. It will, however, allow them to see if there is any mottling and/or scalloping of the intestinal walls.

There are some people who are "early" enough in their CD that even an endoscopy won't pick up any damage, though. Like MG, if a person is seronegative for CD, it can be diagnosed through a process of elimination. If a person has a positive blood sample, then they definitely have CD, but if they test negative they still MIGHT have CD. For some people, the ONLY "test" that works is a GF trial diet.

I forgot to ask if your kids have ever had skin rashes that took forever to heal - itchy or not. Some people who have sores/lesions that show up for no good reason (or sometimes a REALLY bad case of acne) may actually have Dermatitis Herpetiformis (DH), which is the dermatological manifestation of CD. Usually these sores will cause a "crater" when the blister on them pops.

About 10% of people with DH will NOT test positive for CD; however, if a person has DH, they AUTOMATICALLY have CD (I'm one of those people). I had sores that would crop up from time to time, and nothing would help. It wasn't until our daughter's CD diagnosis 2 years ago that I even made the connection - once I started on a GF diet, all of those sores started clearing up! There's no telling how long I had CD (I had rashes on and off since I was a child), because I didn't have any of the "typical" symptoms that would have made a doctor suspect it in the first place.

I also found out that I had tested positive for a wheat allergy back when I was 9, but we never did anything about it, because I never had any noticeable problem with it. Have your kids been tested for allergies, by any chance? If they are allergic to wheat, they might not test positive for CD, but that allergy could be causing a lot of their problems and a GF diet would definitely help.

Sorry to go on so long - just wanted to throw that out there for ya!