i was the same way and technically died a couple times.I beat it with the help of a brilliant naturapath and can now eat like normal.contact me if you would like more info.
To answer your question directly, Domperidone has far fewer side effects than Reglan. FAR fewer. I've also heard something called Iberogast can help, but I don't know much about that (yet).
Have they found a cause for the illness yet? Diabetes only accounts for about 20% of all cases. 36% of cases are idiopathic
can develop into gastroparesis.) The other most common cause is post surgical. Other causes, too many to list. (Getting tested for Addison's Disease, myself, for example, although it's not likely since I really, really don't fit the profile.)
Take your daughter to go see a naturopath for opinions. So little is really understood by western medicine about the condition (including the **** we have to go through because some docs will tell you "oh, it's in your head. Here, pop a pill.") that going a more natural route will likely have as good a shot at helping.
Here is a great January 7, 2009 article titled, Gastroparesis: Current diagnostic challenges and management considerations:
http://www.wjgnet.com/1007-9327/15/25.pdf
It touches on everything from symptoms and evaluation, diagnostic tests and various treatments.