According to a report in the Turkish media on July 10, Hedo Turkoglu underwent gallbladder surgery while in Turkey.
Here's a translation of Turkoglu's quote via Real GM:
The doctors advised me to undergo surgery on my gallbladder so I won't have any problems in the future. So we made an according decision. The doctors wanted to get any suspicions on when some sort of discomfort might occur out of the way. So we decided to put that risk out of the way. I believe I will be able to join the national team in a short while. My return after the surgery will be in 3-4 days. Because of that the doctors wanted to perform this surgery right away.