How often do your babies have dirty nappies at this age, and what is it like? Sorry for the odd question and I'm probably being a paranoid mother here but DS1 was dairy intolerant so we had constant diarrhoea for the first three months until we realised what was wrong, and I cut out the dairy from my diet. He then settled to a dirty nappy once every 2/3/4 days ish.
DS2 has shown none of the same signs, no reflux, no screaming/colic, very happy and chilled. By about 3 weeks, he was also on a less frequent dirty nappy regime, and it was mustard colour and consistency.
However, for about the last 3-4 weeks, he has reverted to pooing between 4 and 8 times a day, and it is so liquid it just soaks straight in, or runs out over the sides.
Because of DS1's problems, I've got myself in a state about whether this is normal or not. I've spoken to my HV and a nurse about it, and they just say as long as he is gaining weight and happy in himself not to worry. They may be right, but as they seem slightly surprised that I am still BF and have not started solids 
, it hasn't really reassured me that they know what they are talking about.