President Shimon Peres had hernia surgery on Friday at Sheba Medical Center, Tel Hashomer, outside Tel Aviv. His doctors said the operation was successful. The abdominal hernia was discovered during the president's state visit to Canada and treated by Peres' personal physician and Sheba deputy director Prof. Rafi Walden. Peres completed his visit as scheduled, returning to Israel on Friday. He was admitted to Sheba and underwent surgery the same day. The President's office said the operation on Peres, who is 88, was successful and that he was scheduled to be discharged from the hospital on Sunday. Walden said after the operation that the hernia repair went well and that the president awoke from the anesthetic feeling well. Peres spoke with his family and his advisers and asked them to express his deep gratitude to all those who wished him well.