Hi. my mom, 54 years old had laparoscopy cholecystectomy in the end of November 2014. Elevated AST, ALT and GGTP after operation( GGTP 160). GGTP level checked every month. Falling down slowly until 60 in the end of december. Aspat and Alat normal until december. Checked GGTP now- again 150. Ultrasound before operation normal. She doesn't drink alkohol/take drugs. What can be the reason? What should we do?