Before I got diagnosed with Gastroparesis, when I would go to the ER multiple times for fluids doctors would "assume" that it was anxiety causing all of my vomiting, nausea because they didn't have a "real" answer as to why I was vomiting so much. I'm a very happy, easy going person and anyone who knows me will tell you I was the last person that would struggle with anxiety. It would sometimes be so frustrating because I knew something was wrong and had to continually go back (my visits were getting to once a week for fluids) BUT there was nothing they could do to help me besides give me a bag of fluids and send me home.
Once I was diagnosed, and my gastric pacemaker was placed when I went to the ER they automatically wrote it off and said oh, it's probably something with the settings BUT I come from a small town and they don't have a lot of knowledge about the machines or GP in general. I recently switched my care to a bigger city about 3 hours away and when I am in need of an ER we drive there instead. The care in the bigger city is SO much better and they always know exactly what to do.
As far as going to the ER, I used to have an NJ feeding tube and it would continuously come out of place due to vomiting, I would have to go to the ER each time. Sometimes dehydrated, sometimes low on potassium and magnesium and sometimes low blood sugar. Often times I would let go until I have syncope "episodes" because I hated going to the ER and risking that I may catch something else. NOW that I have the j-tube and the port I don't find myself having to go the ER as much.