You could possibly be lactose intolerant. I would get tested for that. I was just diagnosed with gastric emptying. Basically I feel full really fast, want to vomit sometimes after eating, etc. My h. pylori was negative, but try to get some more tests. done.
Gastritis? Maybe, because calcium requires more acid to digest than most other foods, but otherwise no. IBS? Yes, if you're lactose intolerant.
But let me get this straight: bloating and stomach pains brought on you eat fatty or highly fibrous foods? Request from your doctor a gastric emptying exam, since these may also be symptoms of gastroparesis. Delayed gastric emptying also explains the gastritis. An h. pylori check should also be done. You may also want to explore the possibility of gallbladder issues.
Good luck.