Feeling sick after meals??

EDIT: I also have fatigue and find it very hard to eat, I often miss meals due to the nausea (making me lose weight that I can't really afford to lose). I feel very full afterwards and seem full for hours and often have lots of regurgitation. If I have any pain (which is not too often, thankfully) it is in my lower abdomen.

My GI doc put me on Erythromycin three times a day (oral) but did not tell me why?

Your doctor will be trying to establish if you have a bacterial infection.  This is why you are on this antibiotic.  Constipation can cause bloating.  Try a food diary to root out food intolerances and eat lots of fruit or use a laxative to treat the constipation.  Constipation can make you feel sick, put you off eating and lose weight.

When you get the pain, does it move about?  IBS could be one possibility but other causes will need to be ruled out first.  Your best option is to keep going back to your doctor and ask for more tests until you get a firm diagnosis.  I had to wait three and a half long months for an IBS diagnosis..

Make a list of your symptoms and possible causes; ask your doctor lots of questions. Sometimes, doctors will not give you the information you need unless you ask for it.

GPS should never ignore you!

Have they checked if you have an intolerance ie gluten lactose

There are a few things it could be 

Maybe get them to check your gallbladder (scan) pancreas

All of the above would cause what you’re describing 

See a different gp and hopefully you’ll be feeling better soon 

For 6 months you have been seeing a doctor who seems to ignore you and you go on suffering. You don't know what to do any more. Why don't you see another doctor?

UPDATE: