Hi, Welcome to Health care magic forum.
                 Don't worry it is not a cumbersome procedure,She may be given mild sedation, but she wont be unconscious , it is to avoid her 
anxiety.  
                 The causes for the continuous 
vomiting, and loss of weight may be due to the drugs she has used after having 
hip surgery, as the vomiting has started after the surgery.  
                  Any how after the test, and treatment  she will be fine. 
                 I usually prescribe to my patient with such symptoms injection pf metachlopramide. omerazole, 
domperidone. 
                 Avid giving her spices,junk foods, and oily foods.   
                 Wishing for a quick and complete recovery. Thank you.