it took a few weeks for DD to become an "every day" regular after we started solids (maybe 8 weeks or more) - before that she was up to 10 or 12 days. it was very stressful for me so i know how you feel!

if the consistency is, as my health nurse put it, "like toothpaste" then he isn't constipated. the pushing noises are simply a progression from the simple BF poos to the more complex solids ones. offer a drinking cup of water with all solids - he may not take it for now, but he will get the idea. once he ups that fluid intake to counter the solids, things should get a whole lot more regular. DD is now at least once a day, sometimes twice. she will let us know she is going with the pushing/grunting, but it is nice and soft so i think it's more about the different sensation (plus i think they have to push a bit to get it to fit into the nappy - no sitting on a potty and letting gravity do it's thing yet!)

hope that has been a bit of reassurance - if things do start to get to the pellet/rabbit poo stage, check with your GP or health nurse what other options you have. you can add foods that will help things along (watered down prune juice helped here at your sons age - now we have prunes or sultanas for snacks most days)

good luck - and enjoy the BLS journey - it's great fun watching them discover new flavours and textures and an enjoyment of good food!