Hello! Thank you for the query. Joints problems and gastrointestinal problem can both appear with inflammatory bowels disease (Crohns disease). Vomiting can be a result of bowels obstruction. Especially if she does suffer from gas blockage, diarrhea, or diarrhea and constipation alternately. ANA can be elevated in Crohns disease. This is the first thing that should be ruled out (as it seems that this is not gastrointestinal infection). To do that she should have abdominal X-ray and enteroclysis (abdominal CT with oral contrast) should be considered. The other reasons of severe vomiting can be peptic ulcer, gallstones, pancreatitis, food allergy, brain tumor, internal ear disease. The next step should be blood work, liver tests, bilirubin, amylase, urine analysis, abdominal ultrasound and endoscopy. Depending of the results some other tests might be necessary. Hope this will help. Regards.