First DD had been feeding well and pooing regularly (up to 4 times a day and once at night) until last week. Suddenly she went to only pooing once every three days and building up such an amount of it that she wouldn't feed as long, got a sore tummy and screamed when straining to get it out. Today she had another episode and screamed blue murder before a huge pile of runny, reddish brown and stinkier poo than previous came out - never seen her so distressed. Still wetting nappies regularly and feeding a little more often than usual - is it diarrhea? Anything to worry about?