I don't take amitriptyline however I take Zoloft and I know the side effects that come with them. Is this the lowest dose available? I would ask your doctor. Its more common for doctors to start you off at the lowest dose available and work you up if necessary. You may just be sensitive to this specific medication. I have gone through many antidepressants until I found the right one. If you aren't feeling right, I would suggest you call your doctor right away. We don't all respond the same way to medications. You might want to ask about
this medication in the anxiety disorder forum to see if anyone takes it and their experiences with it. Sorry I don't have anymore info on this medication. Here is a link though to some info on it:
Yes, you can see a regular doctor about IBS. They can prescribe the same medications that a GI specialist can. I only really recommend seeing a GI to get a diagnosis because they are more likely to order the proper tests but once you get a DX, you should be fine with a GP. Also a specialist gets a little pricey.
I would get a second opinion on that Zelnorm