I developed an intolerance to shellfish years ago (which is a huge shame as I love it). I think it might have been triggered by a lobster food poisoning incident at my sister's wedding (what a nightmare that was!), but it might just be part of a general trend I have noticed that as I get older, I seem to develop more intolerances. I was still able to eat other fish (salmon, white fish, tuna).
Last night we had fish for the first time in a long time (my husband doesn't like fish so we rarely eat it). It was plaice. Today I have had very bad diarreah of the type where you can see last night's dinner pass through you totally undigested. This is what happens if I eat shellfish. Now, the rest of the family (including my 1 year old) are all fine and the fish was bought from a reputable place so I know there was nothing wrong with it.
What I am left wondering is if I have now developed an intolerance to fish of all kinds? (though I eat tuna fish - canned - regularly with no problem)
Any ideas?