BM Issues After Green Light PVP Surgery

10 weeks ago, I had Green Light PVP Surgery for Bladder Outlet Obstruction. I am 82 years. Subsequent to the surgery I had constipation. Gastroenterologist prescribed Linzess. It is helping with constipation. My questions:
(1) How long do I need to use Linzess, which comes with Gas and
Burp issues as well as watery stools.
(2) After surgery, Urine passing is taking longer and 99.9% is emptied in
the first 2 minutes; the rest taking 8 minutes with drips and drabs.

Any guidance would be appreciated.