The umbilical hernia should NOT present any difficulty to the surgeon for the cyst excision...and he will probably repair the umbilicus at the end of the case.
The UH might be caused by pushing, or it could be bad luck: every human has at the potential for a hernia there.
The real question is why there is a stenosis. The first question is: Is it actually stenosis (a congenital malformation)? Or is it another disease such as Hirschprung's, or even eosinophilic proctitis. The first is an error of nerve development in the bowel (this does need surgery), and the second is often an allergy or similar immune intolerance (like to milk....and this rarely needs surgery).
I hope this helps.
You may want to ask your doctor if a biopsy would be helpful. Usually, this can be done in the office (or they could do it during the upcoming procedure).
they are saying 2-3 weeks hospital time?
1 year full recovery?