DS2 has been in cloth since birth but has had a red raw bum despite me washing everything properly and treating him with a combination of Morhulin, Metanium and Canestan. The only time it clears up is when I put him in disposables for a couple of days when it just disappears and as soon as he's back in cloth it comes straight back.
I'm wondering if it's the fleece liners, I did have reservations about a synthetic fabric next to his skin but from my point of view they work well. Don't want to use disposable liners, what are my other options?