What can a doctor find by doing an ogd/egd? when experiencing malabsorption and high chances of autoimmune disease.. what other tests are associated with autoimmune diseases? ... like ana is one of them or some mhc markers.?

EGD: EGD tells a lot. .Can tell if inflammation , can take biopsies from the esophagus, stomach, duodenum to diagnose eosinophilic esophagitis, , H. Pylori ( that can also be diagnosed by breath/ stool) and n malabsorption make the definitive diagnosis of celiac disease. W/ultrasound may note pancreatic issues. ANA would not help nor would other markers.- they are often negative in GI diseases.