Over the past couple of years of eating around Budapest I've felt that something "fishy" was going on at some of the well-regarded, up-market local restaurants I frequent. But I was never able to put my finger on what it was. Now I have, and I'm going to tell you. But first, if you're reading this while eating, stop.

I'll start by reprinting an email I got a few days back from a regular source, K.R., who wrote the following:

I have been looking for a good oily fish to eat instead of salmon, I'm sorta grossed out by salmon now! So I investigated butterfish because it is now on all the menus. I read that real butterfish is high in omega 3 oils so I was excited. A few weeks ago I asked the fish guy at the csarnok if they sold butterfish and he said yes, frozen (it's a pacific fish). So today I asked for butterfish and he automatically gave me a bag of [something labeled as] Escolar. It looked like the butterfish we get in the restaurants so I was fine with it. I got back to the office and checked [online]… Turns out Escolar is usually wrongly called butterfish… real butterfish actually looks more like flounder and not really like the thick steak-like pieces they serve here! I also think real butterfish is very expensive. Apparently in the US there is a big controversy about people selling and serving Escolar and calling it other names, like butterfish.

As for why people would call a fish like Escolar "butterfish" - vajhal in Hungarian - you can probably guess that it's not just because "butterfish" name sounds tastier. It's because Escolar, if not prepared correctly, or eaten in quantities larger than 150 or so grams, can produce some very nasty side-effects, namely keriorrhea, a.k.a. oily diarrhea, oily orange diarrhea and orange oily leakage.

If that's not enough to put you off, I found multiple sources citing this more lurid description of the Terror of Escolar:

The discharge can stain clothing and occur without warning 30 minutes to 36 hours after consuming the fish. The oil may pool in the rectum and cause frequent urges for bowel movements due to its lubricant qualities and may be accidentally discharged by the passing of gas. Symptoms may occur over a period of one or more days. Other symptoms may include stomach cramps, loose bowel movements, diarrhea, headaches, nausea, and vomiting.

I'd say the good news is that it won't kill you, except if you're going through all this you may wish you were dead - especially if it starts happening during dessert. Oh, and by the way, the oily mess oozing out of your rectum may "smell of mineral oil." Check please!

So why does Escolar seems to be gaining in popularity here in Hungary just as people in other parts of the world are waking up to its poopocalyptic dangers? That should be pretty obvious: It's tasty and inexpensive, and unless someone goes looking for a reason not to eat it - or eats too much of it - no one will ever know.

I am not suggesting, however, that this is some sort of scam being perpetrated by restaurateurs, or even the wholesalers who supply them. Instead, my guess is that people in the business haven't connected the dots. There is also the possibility that fish wholesalers here have been selling both "real" butterfish and Escolar interchangeably. Which wouldn't be at all surprising, especially when you consider that in Hungarian, the word rák can mean both prawn (shrimp) and crab.

I called a couple of friends in the local restaurant business to see what they knew about all this. Both said they had also been dubious about vajhal, because it is so cheap (around Ft 1,250 a kilo wholesale) compared to other sea fish of comparable quality, and because they'd never seen it on menus anywhere else except Hungary. As one of them (a Hungarian) put it: "Hungarians don't know anything about fish, so what are the odds we would be the ones to discover some great fish no one else knew about?" But they didn't know the Awful Truth until now.

All this said, I've had vajhal on several occasions, and never had any of the terrifying problems outlined above. (The picture up top is from this review of the Stand Bistro.) And I might order it again, even knowing what I know, because, well, it's cheap and tasty. I'll just make sure I'm not seated too far away from the bathroom.