Bei Bei, a giant panda cub at the National Zoo, appeared to almost smile Tuesday morning after gobbling down medicine cleverly hidden in a sweet potato to help him recover after a surgery to remove bamboo lodged in an intestine.

In a photo put out by the zoo, the 1-year-old Bei Bei looks well. He has a bare belly because the area was shaved for the emergency lifesaving surgery he had Friday after zoo keepers noticed he was not his usual self.

But his black and white coat is already growing back, authorities said.

Bei Bei’s mother — Mei Xiang — is with him. Zoo keepers said she “spends large blocks of time in the yard eating bamboo,” while he “rests and sleeps inside.” Zoo officials described this recovery as “very important for the healing process.”

The zoo’s panda house is closed to help Bei Bei recover. On Monday afternoon, Bei Bei was climbing around his den so zoo keepers reintroduced his mother Mei Xiang to “help him settle down.”

In a statement, the zoo said that “after an initial period of high activity during the introduction, Bei Bei nursed for 20 minutes and they both fell asleep.” Post surgery, zoo officials said, Bei Bei has successfully nursed three times.

Zoo keepers are keeping Bei Bei off bamboo for now, figuring it is “too much for his digestive system.” His mother leaves him to eat, and then they are reunited. Bei Bei’s diet, for now, consists of biscuits and sweet potatoes. Zoo keepers said they put antibiotics, antacid and pain medication inside the sweet potatoes. He is reported to be bright and alert.

On Thursday, zoo keepers had noticed that Bei Bei was behaving oddly, sleeping more than usual and showing little interest in food. He also seemed nauseated and threw up twice.

The cub was taken to the zoo’s on-site veterinary hospital Friday morning and underwent an ultrasound screening. An endoscopic exam found a dense mass of bamboo the size of a lemon atop his small intestine. The bamboo had been only partially digested. Such a blockage is a rare ailment for giant pandas, officials said. Quick-thinking and expert care, they said, is what likely saved Bei Bei’s life.