Megastar Amitabh Bachchan's scheduled abdominal surgery went off smoothly Saturday morning and he is now resting in the hospital room, says his son, actor Abhishek Bachchan.

"The abdominal pain was due to the pain that had started during the injury that he (Amitabh Bachchan) had got during 'Coolie' (in 1982). He is operated now and the surgery went on for two to three hours. It has gone smoothly," Abhishek told reporters at the SevenHills Hospital here.

"He has been shifted to the ward and is out of the operation theatre. It was successful, and he has been kept under observation by the doctors," added the junior Bachchan.

The 69-year-old veteran was happy and cheerful before being wheeled into the operation theatre in the morning, doctors attending on him said.

He was wheeled in around 9 a.m.-9:30 a.m for the surgery, and his family was with him.