Buntibear, I am in the same place!
M passed a milk challenge on the 6th so last Sunday I gave him baked pizza with cheese and the poo was truly gross and liquid. Rang the dietitian and she said to hold off the milk even though it is in the middle of the weaning chart they gave me to follow before the blood tests and the milk challenge were done. They said that while the protein of baked cheese is more altered by cooking, being cheese it is more concentrated. So we tried warmed up cow milk (like in the challenge) and his eczema returned, itching, smelly poo, however not diarrhea. We tried boiled cooled milk and still rashes. So we are off cow milk for today and no new spots. On Monday after a 2 day break I will buy him a croissant. That is the first stage in the milk introduction chart (baked goods containing milk powder, e.g. Reach tea biscuits). We will see how this goes. But yes, itching, rashes, flatulence, diarrhea - sounds familiar. Best of luck to you and Olly!