"Diabetes" is the general term or (believe it or not) any condition that makes you pee a lot. The two main types Type I and II usually involve polyuria through high blood sugars. However another type of diabetes exists. Diabetes Insipidus is the condition of the body where ADH (or Antidieuretic Hormone), which helps you maintain water has its production compromised. This is a dangerous situation as you can become dehydrated.. FAST.
The best answer for this question would be to talk to the cashier, in situations like these the customer is always right and knows exactly what they want, and if that doesn't work out ask the manager so he can get the correct coffee he wishes for.
