Why do babies get really bad diarrhea when they are teething?
The theory is that they are swallowing extra saliva, and that teething can put them off their food, causing runny stools which will more likely give diaper/nappy rash. My LO has just gotten over her rash – I recommend Ashton & Parsons Teething powders, they help to re-balance things. Try to give him as much ‘airing’ time as possible too.