What about sphincter of oddi? Did they check to see if the ducts were all working OK? I'm with you as far as I had my GB out in Nov too. It's been a rough ride and for the most part I am better, but still having problems. I haven't gone back because I am so sick of them telling me nothing is wrong AND it's expensive. Since I stopped losing weight and in general feel better I've just been dealing with it.
I've read others have an ERCP which is an examinations of the biliary system.
I've never had right sided pain at all, and I didn't have any stones. My GB was functioning at 0% and was inflamed. I had cramping/spasms in the lower left region prior and after removal (worse after removal for months) and now they have finally lessened. What's new the last 3 weeks is pain under my ribcage on the LEFT side. It's not cramping but a steady/long term pressure pain. It can last a few days, worsen, then go away completely. I can't get comfortable, it's like someone is just pressing their fingers into me - I can't lay on my left side at all. I have NO idea what that is and hope it just goes away.
OK didn't meant to turn that into me there

I wouldn't think adhesions would form that quickly, not enough to cause problems - hey I am no doctor.
I do wonder about your biliary system and if it's been checked. I've read a lot of people can have those problems after GB removal. I see you are in the UK so I don't know what your options are with health care. I'd hope you'd be able to make suggestions like this and get some tests if you have not already.