is surgery needed even for a solitary mobile asymptomatic gallstone?

Hello. Thank you for posting.

Gallstones may cause no symptoms and are occasionally discovered as an incidental finding when abdominal imaging is carried out for some other reason. For some, asymptomatic gallstones can be left alone as some patients with asymptomatic gallstones will never develop symptoms.  However, surgery might still be recommended for many due to other factors. For example, patients with diabetes mellitus are advised to have a cholecystectomy (surgical removal of the gallbladder) for asymptomatic stones because these patients tend to have more complications related to acute surgery than patients without diabetes. 

Your doctor, who knows the specifics of your health, can tell your more. 

Helena