optifast?

When I thought I was getting the RNY from a different surgen, He was recommending a liquid diet for a month so I purchased a month supply of Optifast chocolate, strawberry, and vanilla.  I haven't had an opportunity to try out all these other protein powders that are talked about, but do you think I will be able to just use the Optifast up first before buying more protein powders?  In looking at the food label, it has 14 grams of protein and a lot of different vitimins in one shake, supposidly able to susatin a person to just soley drink these shakes and survive. 
Thanks for your responses.
 

How many carbs?  How many carbs as sugar?  It is a bit low on the protein count, but you could do double scoops.

My goal (which I stole from Kayla) was to make sure every meal or snack had at least twice as much protein as carbs.

the optifast is
3 g fat
20 g carbs/ sugar
14 protein