As you progress on the liquid phase, there'll be less to come out. Your intestine has just been sliced, diced and resected. Expect some strange things until you stabilize a bit more. In the meantime, drink lots of water and work on the protein. Your body is rebuilding itself after the abuse you took in the OR. You have to give it some building blocks or it'll find them in places you'd rather keep, like muscles and bones.
There's a guy in our monthly support group who neglected this part of it post-op. A year later, he is still trying to build his strength back, and can now lift close to 40 pounds. He was weak as a newborn for the first six months post-op, though, and never really knew why.
I worked at it immediately post-op (it's challenging, but do it anyway!

) and I suffered no loss of strength. As a matter of fact, I'm actually stronger than I was because I still have the muscles that lifted and moved that 120 pounds I don't carry any more, so I can use them to do useful work now. I didn't pump iron then, I pumped blubber!!

As always, your mileage may vary, but the principle is sound.
CT