It might not be the fried as much as the indigestible nature of clams...they can't be chewed properly, and are basically swallowed whole. Keep in mind that your wrap was created out of the whole "cloth" of stomach, and could have been badly irritated. I'm not sure the connection, but the vagus nerve could be a piece of this response, as it is affected by your upper GI tract. The diarrhea/dumping is most likely due to the irritation of the wrap/stomach as the clams went through.
Unfortunately, you can't get away from the fact that the new LES you have is made of your stomach, and it will forever behave differently. Hey, the clams can be eaten, but probably fewer, and with the knowledge that you may sufferer afterward.
Before I had surgery, I had a vagus nerve episode at a restaurant, with blood pressure plummeting, and faintness, which sent me to the ER, where they found absolutely nothing wrong with me.
Those of us with quirky GI issues just have to accept some crazy reactions from time to time.
If you know the cause, it often doesn't seem as bad.