CHENGDU, March 6 (Xinhua) -- A giant panda that received stomach surgery in east China's Zhejiang Province is in critical condition four days after the delicate operation, which was the first of its kind in the world.

Sources with the Chengdu Research Base of Giant Panda Breeding in southwest China's Sichuan Province said the four-year-old male panda, Cheng Jiu, has survived a dangerous reflux of gastric juice three times since the surgery and remains in critical condition.

The panda lived in Hangzhou Zoo in Zhejiang for 18 months before the panda's keeper found him eating less and suffering from low energy in late February. He was diagnosed with acute stomach distention.

Veterinarians from the zoo and the panda center as well as doctors from Sir Run Run Shaw Hospital in Hangzhou made a group consultation for the diagnosis of his illness and a plan to operate.

According to the center, it was the world's first stomach incision surgery to eliminate indigestible food, for a giant panda.

Veterinarians said Cheng Jiu was under intensive care.

He needs to fast for seven days after the surgery and take food via intravenous injection.

They said the biggest difficulty now was that his movements could tear the stitches from the operation, which would cause the surgery to fail. Reflux of gastric juice could also trigger inhalation pneumonia, leading to suffocation.

Cheng Jiu weighed 115 kg before the illness. He was examined as healthy before the State Forestry Bureau approved the center sent him to Hangzhou Zoo in 2016.