Is DS constipated?

[spangly]

Hi. I'm not sure if this is the right place for this so apologies if not.

DS is 20 weeks old. He is breastfed. I did introduce a few ounces of formula a week or so ago but haven't given any for the last 3 days. The change in bowel habits started before formula was introduced though so not sure if there is a link there.
From birth ds has always been a frequent nappy filler. However, since christmas he has dropped to one poo every three days or so. I know this is normal in a breastfed baby. However, he seem sin such discomfort for the last day or so before the poo and has really smelly wind. Also when he did poo today it was thick. It was still the same mustard colour as usual and he's doing plenty of wet nappies but surely he shouldn't be straining? It's made me wonder if he's constipated and if so what I should do about it?

[beansprout]

Ds used to gurn for England when pooing (he was b/fed). Does he seem to be in real discomfort? Real constipation tends to involve a different type of poo, not just more of an effort to get it out but the formula just may have played its part there.

[spangly]

Hi Beansprout - thanks for the speedy response. DS does seem to be in discomfort. He's been thrashing his legs around a lot and has been quite grizzly. Also, for the last 2 nights he's been unable to sleep and has kept me awake all night. He did a poo this evening and seems to have settled much better this evening so I'm wondering if there's a link there. I guess the formula may have played a part in consistency - poos used to be very runny (sorry if tmi).

[spangly]

Well this morning we had the mother of all nappies. Filled the nappie and the bodysuit (sorry again if tmi). I'm guessing by the volume that his body isn't just being efficient and using up all the nutrients from the milk but is instead storing the waste?