Bollywood megastar Amitabh Bachchan's condition was stable Thursday, a day after he underwent an abdominal surgery, but he will be out of action at least for a month.

After the two hour 45 minutes surgery for intestinal inflammation - suspected to be a fallout of an earlier accident-induced-operation - the actor was shifted to the intensive care unit of Lilavati Hospital here, where he was admitted late Monday night.

The 63-year-old screen icon, who was on IV fluids, was given a sponge bath early Wednesday morning. He may remain on IV fluids for the next five days and will remain in the hospital for the next 10 days.

Doctors said the operation became unavoidable after one of the diverticulitis - small bulging pouches in the digestive tract - that Bachchan had developed ruptured.

It was the second time that Bachchan, one of India's most venerated actors, had undergone a surgery. He had a stomach operation in the early 1980s after meeting with a near fatal accident during a stunt sequence for his hit film "Coolie".

Earlier, the doctors had said the star was suffering from colitis or inflammation of the colon. He was admitted to Lilavati Hospital after being flown in from New Delhi.

Apart from his family members - son and actor Abhishek Bachchan, actress-parliamentarian wife Jaya and daughter Shweta - who were beside him right through, the Reliance Group family members too were at the hospital.

Following the surgery Wednesday, Bachchan was visited by several Bollywood stars and filmmakers including Salman Khan, Sanjay Dutt, David Dhawan and Manoj Desai.

The surgery itself was shrouded in secrecy as the Bachchan family had issued strict orders to the hospital administration not to divulge anything to the media - fuelling much speculation.

According to hospital officials, specialist surgeons were brought in to conduct the surgery in the first floor operation theatre.

Earlier in the day, doctors had said that Bachchan's health was improving. But reports of the surgery, which began at around 6 p.m., fanned fears that all was not well with him.