When I eat shellfish, it makes me sick. Not the typical hives, swelling, itchy etc sick. Almost immediately, I feel like I need to have a bowel movement but can't. Then I vomit. I will feel a bit sick for about 10-20 minutes and then I'm back to normal. I didn't always have this problem. I noticed it about 8 years ago. After having the same thing happen after eating shrimp and then crab I concluded that it was the shellfish. Is this an allergy?

It does indeed sound like you are sensitive to shellfish. You should avoid it if possible.

It does indeed sound like you are sensitive to shellfish. You should avoid it if possible.
I do avoid it. Lucky for me... I was never really a big fan of shrimp. But the crab cakes and lobster I do miss. I was really wondering if its an "allergy," because I don't have the typical symptoms.

Typical symptoms aren't typical for everyone ;)

Typical symptoms aren't typical for everyone ;)
Guess that's why I'm special...