Make sure you know what you get when you order fish at a restaurant. Some restaurants will serve you 'tuna' that will force you to have a very bad day.
Escolar is a type of fish that contains indigestible oil called gempylotoxin which is made up of wax esters. Humans can't digest wax esters and it just passes through the gastrointestinal system. It's not toxic, but that doesn't mean the side effects are pleasant.
Because most humans can't digest the oils, it has a laxative effect that can create quite a bit of unpleasant chaos in your life. The symptoms usually start a few hours after you ate the fish and include diarrhea, vomiting, abdominal pain, nausea and headaches. You could, however, also experience the rectal passage of an oily, bright orange or yellow substance. This is not a loss of bodily fluid and is not life threatening, but obviously not something to look forward to.
Although the oil in escolar is not toxic as such, the loss of fluids through the diarrhea that follows it consumption can cause severe dehydration that can become life threatening if not treated.
