We had our first visit to the vets for illness tonight :-(  so heres the story and the symptoms, the vet is unsure whats wrong so we are back first thing Fri morning.

Sat night Marley stole a cooked chicken thigh, I tried to get it off him so he swallowed it whole
Sunday morning the thigh came back up (phew) still whole but snapped in half
Sunday night he ate the usuall Sunday roast chicken n veg
Monday he didnt eat much but had the odd nibble
Tuesday morning he was sick ALOT (all over my 1 wk old car! argh bless)
Tuesday night he ate a bit of BBQ sausage but no dry food, sick within half an hour
Wed morning refused to eat his dry food mixed with sardines (usually loves this)
I was cooking T tonight and was feeding him pieces of chopped chicken, sick within half an hour again
The food he has eaten comes back up totally undigested, very soon after eating it, his stools are ok but small, he is still playfull and active.

Any ideas?

What did the vet say?
I would say go back to basics and just feed plain pasta and rice with chicken or fish. If his tummy is a bit sensitive i cant imagine BBQ sausage would help.
Are you sure he got rid of all the bone?!

My gr is always sick if he has any cooked chicken, I found this out when he was a puppy and the vet suggested it when he had a dodgy tummy, it just made him much worse and at 2 years old he still cannot digest cooked chicken.  Now raw chicken he is fine with!

I'd leave out his next meal and then maybe try him with a small amount of plain bio yoghurt and honey and if you have some glucose put a teaspoonful of that in his water.  Sometimes tummy upsets can take a few days to get back to normal.

If he is no better tomorrow then go back to the vets.

I have also heard on other threads and boards that cooked chicken can upset some dogs. I am not really a fan of giving dogs human cooked food, as I dont feel it gives them the appropriate nutrition. I think dogs are best fed on  good quality manufactured foods or BARF diet, according to personal choice. The odd treat is one thing, but to have it too regularly cant really be healthy for them...partcularly in a breed that has a tendency to over do it on the food front if allowed to! If I were you I would go back to your chosen dog food.
For now you could just try to give him his usual dog food, but avoid cooked chicken as it may actually be causing the problem.

She said he may have irritated his stomack with the chicken thigh or may have a eaten something else he shouldnt have but with him not having diohrea she cant rule out a blockage but tended to think not as his stomack was soft and she said they usually go tense if theres an obstruction, so shes not sure but gave him two injections, one antibiotic and one to stop him feeling sick, she gave me some sensitive wet dog food to give him, one table spoon every now n then until we are back in the morning and I am also to monitor how much he is drinking.  I cant be 100% all the bone came out, it looked like it did but there could always be a bit in his throat, I guess that could trigger vomiting and not cause diohrea.  Hopefully she will be able to find out whats wrong tommorow. 

If he is bringing totally undigested food up - this could be regurgitation rather than vomiting - mention this to the vet, the bone may have scratched his gullet and not getting down, is he still drinking?  or is this coming back up too?  all things to consider when talking to the vets.  Good luck and wish you all well - hugs for Marley xx