<prompt> Medical treatment of gallstone indicated in AE:GB should be functioningGallstone should be radiolucentGallstone should be radio opaquePatient is unfit for surgery  <response>: For good results, medical therapy should be limited to radiolucent stones smaller than 5 mm in diameter. Stones larger than 15 mm in size rarely dissolve. Pigment stones are not responsive to UDCA therapy to produce a lamellar liquid crystalline phase in bile that allows a dispersion of cholesterol from stones. Ursodeoxycholic acid decreases cholesterol saturation of bile. UDCA may also retard cholesterol crystal nucleation. 