That doesn't sound like a food allergy to me. When we first started solids my LO went a couple days without pooping and then had some very different looking poop diapers. It was just because he had not had anything except breastmilk up until that point and his little digestive system had to get used to it and adjust. I have read in Baby 411 that it's typical for them to have some changes like that when starting solids. My LO also had diaper rash for the first time when we started solids. Once his poop got normal again (new normal compared to before) the diaper rash cleared up. One thing we do when he has a diaper rash is wipe him with wash cloths instead of wipes. You might already be doing this since you cloth diaper. Just try to stay on top of it and glob on tons of whatever paste you're using.
Also, my LO has been drooling and putting everything in his mouth so much that his face has been really red and splotchy at times. It also has gotten chapped from the winter air. This happened around the time we started solids too and I was concerned it was the food (along with the different poop). We called and they said if it was a food allergy it would most likely be all over his body. So we've had to glob Aquaphor on his face now too. It's hard when they have several things going on. Turned out none of ours were related.