I was diagnosed by endoscopy and have been gluten-free for six months now. Initially I continued to get bloating, stomach pain and D. All that has pretty much gone now... in my own case the following brought around an improvement.
I gave up dairy pretty soon after gluten as my stomach was still v. uncomfortable and continuing problems with D. This really helped.
Then I discovered that even gluten free oats gave me stomach pain and D so gave them up. I thought I might be having a reaction to the protein found in oats but my nutritionalist looked at it from another angle... maybe it was the type of fibre that was causing the sore stomach and D. She might be right because I then noticed I had the same problem with lentils. I used to eat oats and lentils all the time so I am going to try them again after a year gluten-free, in case the pain is caused by eating this type of fibre where there has been a lot of villi damage, which can take up to two years to repair (according to my NHS dietician).
The other thing that gave me problems was soya - it is so many gluten free products in the UK. As I love cakes and biscuits I was eating these and they contain soya flour - more stomach ache! So gave it up too.
I think it is a lot of trial and error unfortunately but from what I have read the above foods can cause problems.
I'm told a food diary might be worth doing... I found one on an IBS website but haven't tried it yet. Have you done this? For me gastro symptoms are no longer the issue, just vertigo, but of course it might be nothing to do with coeliac disease.
Also find ginger in hot water a v. soothing drink when I feel a bit stressed. It calms the stomach and somehow makes me feel more relaxed.