This article has some good information.
The pre-surgical diet guidelines are for general purposes only. However, your physician or surgeon may require you to follow an alternative plan. In that case, follow your physician’s instructions rather than the guidelines in this document. It outlines how to change your diet fourteen days prior to surgery, the day before surgery, the night before surgery, and the day of surgery. It also includes some examples of what is allowed on a clear fluid diet and what is not allowed.
Presurgical diet guidelines are provided by the specialists at Hospital for Special Surgery.