DS vegetarian question PLEASEEE!!

 i'm a vegetarian thinking of doing a duodenal switch (BMI of 60 and have been researching for 6 months now).

 

i do not eat eggs or fish, but i do have dairy.

 

i'm not worried about being a vegetarian DSer - i know i can get all my proteins from various vegetarian foods and protein shakes.

 

my concern is:

a) is there a chance that i will become lactose intolerant? is there any way to avoid it?

b) will beans, lentils, etc... give me gas?

 

if i become lactose intolerant and i cant eat beans and lentils - there is isn't much else to eat....as these are my main sources.

 

what can do to make sure i won't have those problems before i do the DS? i need to be certain before i do the surgery - i'm worried that my health post-op.

 

any advise will be very much appreciated.

 

thank you:)