NostraHistoria,
Good luck with the liquid diet! It will be 3 years soon since my son started enteral nutrition as a main treatment and main source of nutrition for his Crohn's. For the most part he is not able to tolerate food so he drinks the formula. Since you are in PL I think you might find special formula made by Nestle there. It's called Modulen IBD. Might be expensive though if you'll have to pay out of the packet but maybe your Doc. can prescribe it for you (don't really know how it works there).
Once again – good luck.
Chachka (12 yo son with Crohn's)