text_1: Hello, my dad, 68 years old, has gastritis,  it did ache occasionally over the last several years. The other day, he went to hospital to have medical check-up with endoscopic ultrasonography, and found GIST with about 1cm in size. Doctor told him that he may consider surgery or not, it is up to him. What are we supposed to do? will it develop to bad condition? any suggestions?  I 'm looking forward to your early reply. Thank you so much.
text_2: How is an endoscopic ultrasound performed ?