Dear friend,
with a history of such
severe vomiting, and now
abdominal pain radiating to the back, a history of diabetes, I would seriously recommend you do visit the ER again.
I would also suggest asking the ER doctor to rule out a condition known as diabetic
ketoacidosis, and also to rule out
pancreatitis before he sends you back home today.
I'm not saying that you could be having such a serious condition, its just that, it would be better to rule them out just to know we are safe.
Diabetic ketoacidosis is seen in diabetics dependant on insulin, and occurs as a result of uncontrolled glycemic levels, is accompanied with
dehydration, and the blood going acidic because the liver stops using glucose in the way it should normally do.
Pancreatitis on the other end is an inflammation of the pancreas that occurs because of many different causes including stones, alcohol, certain drugs and so on. The extent of damage depends upon severity, the greater the delay, the worse it gets...so do get a clear chit on it.