Hi Kirsty_Lee,

Green poo is normal for FF babies, they are not able to absorb all of the iron content in the formula and so the body gets rid of it in their poo. Mustard/curdy poo's are normal for BF babies as the iron is more easily digestable (sp). As for teething the poo's just seem to become more runny and acidic in my case..still green tho lol

Hope this helps!