ANKARA - Turkish Prime Minister Tayyip Erdogan underwent a successful medical procedure on his digestive system and was in good health, his office said on Saturday.The planned 30-minute procedure was the second and final phase to keyhole surgery performed on Erdogan's lower intestine on November 26, it said."The prime minister is in very good health. He plans to continue his routine engagements during the week," his office said in a statement.His office did not say when the procedure took place, but Turkish media reported that Erdogan, 57, had been taken to a hospital in Istanbul late on Friday.Erdogan, whose Islamist-rooted AK Party won a third consecutive term in an election in June, is by far Turkey's most influential politician. Having led Turkey for the past decade, he dominates the political landscape, and all key decisions rest with him.Two consecutive cabinet meetings were cancelled while Erdogan recovered from the surgery in November despite there being four deputy prime ministers.The government has been tight-lipped on the nature of Erdogan's ailment, fueling media speculation the Turkish leader was being treated for cancer.But a doctor present at the operation in November has said "harmless" polyps were removed. Polyps are abnormal growths of tissue that can be cancerous.Under Erdogan's rule, the overwhelmingly Muslim country has become one of the world's fastest growing economies and a powerhouse in the region.There is speculation that Erdogan wants to move Turkey to a presidential system of government, with the intention of becoming president himself, as under AK Party rules he cannot serve as prime minister for more than three terms.