His Majesty the King had excess fluid on his brain and doctors adjusted a drainage tube in his abdomen for 75 minutes on Friday to treat it with satisfactory results.
The Royal Household Bureau issued a statement updating the King's medical condition around 11pm on Friday.
On May 2, doctors inserted a tube in the abdomen to drain excess cerebrospinal fluid from the spine.
On Friday, they noticed facial twitching and an x-ray showed there was excess fluid on the brain. The physicians adjusted the drainage tube from 6.30pm to 7.45pm, with satisfactory results, the statement said.