"While the surgery went well and doctors are optimistic that the rocker will make a full recovery, the fact that he was exhausted due to his rigorous schedule prior to the surgery and coupled with the fact that he has diabetes, the surgery has taken its toll," his website said. "The main focus and concern right now is that he is able to rest, recover and maintain good blood-sugar levels while doing so."
The 47-year-old rocker and reality star was discharged from a San Antonio hospital following his emergency appendectomy on Monday.
Because of his health, Michaels' tour dates through April 24 are being rescheduled.
Michaels was diagnosed with diabetes at 6. He has raised $100,000 for the American Diabetes Association on this season of Celebrity Apprentice. On the series' most recent episode, Michaels was visibly shaken after hearing his 9-year-old daughter, Raine, may have diabetes as well.