As Crystal said Metro goes hand in hand with LS and Lactulose.
Ask for an RX and shop around online for the best price. Your general Vet may have a better price too.
Also ask for an RX for the Lactulose, and get it filled at Walmart or Costco (bigger bottles for cheap prices).
Not sure about the shunt not closing...hmmm....I would def. ask Olga about that
And sorry, but Joey will never be a normal dog, but with the proper diet, supplements, and regular Vet checks, he can come pretty darn close!