hernia repair and tummy tuck

I had open Roux-en-y bypass surgery 5 years ago. 6 months after I had a double hernia repair below my belly button.
Now, I have a very large hernia above my belly button.
I have lost 102 lbs. altogether.
Why is it not recommended to have a hernia repair and a tummy tuck at the same time?
In a tummy tuck doesn't the doctor bring the muscles together and tighter? Wouldn't that help to re-enforce the
wall protecting the intestine from another possibility of another hernia?  And if I do have the hernia repair, will I still be able to have a tummy tuck? If so, how long after should I wait? The hernia is about a small fist size.
Thank-you for any info. I am scheduled for the hernia repair this Friday morning.

[little163]

my son is going on 2 years he is 19 has lost 285 lbs and is having severe stomache pains his insurance was cut off in aug and he has been to the er 2 times the last time he had keytones in his urine and his sugar was 262 he can not hold nothing down not even water he was given pain pilols then released please help