Liquid Foods for Bodybuilding

Hi guys, Im suffering from kidney stones and have been for the last 2 months, am getting them removed next month, so a bit of a wait.
Its making me EXTREMLEY constipated, and Im having to down mostly liquid meals, as I dont want to keep using laxatives all the time until the stones are removed.

So what foods can I take in liquid form to help stop from losing muscle?
So far Ive come up with
Whey protein

Yes this is extreme but if i eat anything solid Im extremley BADLY blocked up. Until the kidney stones are removed (they are big) theres not much else i can do.

pleae let me know any liquid foods u can think of.

Its not liquid, but if you blend up eggs + almost anything else - veg, turkey bacon, cheese. Put the liquid into a muffin tray and cook in the oven, you get a light and fluffy quiche.

You could also just make protein milkshakes/smoothies with fruit, nuts, cottage cheese etc.