The popular fish that might ruin your evening—and your clothes

Two years ago Tom Duffy, a 37-year-old father of three, was vexed and perplexed by a bizarre case of gastrointestinal distress he experienced one Saturday morning. Unaware of its source, he initially blamed a Thai dish he'd eaten the previous evening. Laughing it off, he changed and drove over to Starbucks with his three children in tow. Unfortunately, it wasn't over. He found himself heckled by his youngest while they walked through the parking lot because he kept his hand strategically placed on the back of his pants to prevent an accident while waiting in line for his latte. The following week, feeling recovered, he finished off some the delicious fish they'd purchased (and enjoyed so much the week before) from the local market in the Wayne section of the Philadelphia suburbs. "That butterfish stuff," is what he remembered calling it. "That was delicious." It was. But soon after consuming the fish, disaster struck again: The trouble returned, this time in more substantial, uncontrollable bursts.

The next morning before work, his wife asked him why his pants were all wet. He decided to take a sick day. Home from work and running back and forth to the shower, Duffy did some minimal online research and found out the ugly, messy truth about the fish he'd eaten: Sometimes it makes orange oil shoot out of your ass.

Incensed, Duffy decided to fight back against the fish market. Over the next few days he faxed them 14 pages of highlighted information from the research he'd done. He attached a hand-scrawled note, accentuated with dollar signs and written in all caps, explaining that he missed two days of work and ruined five pairs of pants because of their "butterfish." He chastised them for not letting their customers know about the possible side effects. The fish market, like many around the country, plead ignorance and refused to respond further. Still, Duffy notes that since his oil-slicked hours of humiliation, he hasn't seen the butterfish sold again. A minor victory, whose only victims were five pairs of pants and two office chairs.

Duffy is like many other diners all over the United States who unwittingly eat escolar, the deep-sea fish found mostly in tropical waters. Sold in many restaurants and markets as "butterfish" or "Hawaiian walu," escolar usually runs as an $18 entrée special at many casual dining restaurants, and can be purchased in fish markets for about $11 to 13 per pound. Some trendier spots prepare it on the grill so that its true "richness and flavor" can be more easily savored. Sushi restaurants occasionally serve it as "super white tuna" or "king tuna." Most diners who try it love it, even those whose seafood consumption is never more adventurous than shrimp cocktail or Gorton's fish sticks. In 1999, the New York Times touted it, quoting Jeremy Marshall, chef of SoHo seafood palace Aquagrill, who likened it to the "foie gras" of fish. A quick Google search of "escolar dishes" results in myriad local and national newspapers praising restaurants for having it on its menu. Conversely, all of these reviews usually end with a caveat that often reads like this one pulled from a 2004 New York magazine story called "The 'It' Fish":

"[B]ut in places like Hawaii, where it's a by-catch of long-line tuna fishing, it's known colloquially as the Ex-Lax fish, thanks to its high content of indigestible wax esters (remember olestra?). In the Canary Islands, food writer Harold McGee has noted, it's considered a folk medicine."

For a follow-up online search, plug in "escolar" and any variation of "anal leakage" or "diarrhea" and you'll find plenty of message boards and blogs dispensing harrowing tales similar to Duffy's. Some of these stories offer disturbing, long-winded narratives that begin with a mysterious expulsion of gas and end with a destroyed pair of khakis at a romantic dinner, or, in some cases, a trip to the emergency room by those who feared that their insides had melted.

The cause of these unfortunate gastrointestinal disasters is usually escolar. The reason is simple and biological. According to Dr. Ian Reichelderfer, chief of clinical gastroenterology at the University of Wisconsin, escolar is laden with an overwhelming amount of wax esters, just like the ones found in notorious olestra, the original ruinous food additive found in Wow! chips and other miracle fat-reducing snacks of the late-'90s. Dr. Reichelderfer explains that the 20 percent wax ester content found in escolar causes the orange, oily discharge to blast out of some people.

"It's like taking a big slug of mineral oil," he says.

In 1990, the FDA issued a warning against Escolar exportation due to the unpleasant evacuation results. It was lifted a short time after the fish was found to be "nontoxic"The effects of escolar are well known by most fishmongers and chefs, but due to extremely flexible rules handed down by the FDA, they don't have to disclose its possible side effects. One fish distributor, Tim Lauer, of Minneapolis-based Coastal Seafood, has nothing but praise for the fish and admits that, anytime it was available, it was an easy sell.

"Then some of our customers would have these, um, 'issues,' and we'd stop selling it," says Lauer. Soon, though, demand would outweigh complaints, and they'd restock, until finally, "It got to the point where we just decided it's not worth the risk. We stopped selling it a few years ago. It's a great-tasting fish, though."

As early as 1990, the FDA issued a warning bulletin recommending the cessation of escolar exportation due to the unpleasant evacuation results. It was lifted a short time later because the fish was found to be "nontoxic." Meanwhile, Japan banned sale of it the fish outright, a ban that continues to this day. In 2007, the Canadian Food Inspection Agency issued a "fact sheet" about escolar that alerted customers to the potential for adverse effects.

The whole thing raises a serious question: Even though escolar lacks toxicity, shouldn't there be a more aggressive push by the FDA to encourage those who sell it to warn their customers? FDA representative Stephanie Kwisnek says yes and offers this add-on:

"The advisory doesn't prohibit escolar from being served, but merely informs processors that there may be some unpleasant side effects from eating it and that they may wish to inform their customers. If FDA found that a seafood processor was misbranding escolar or that the fish was adulterated in some fashion, the agency could take regulatory action."

In reality, "misbranding" seems rampant. When asked if selling escolar as "butterfish" or "walu" or anything else met the criteria for "misbranding," Kwisnek acknowledged that it did. Her solution?

"Report it."

From there, the bureaucratic machine can offer the standard wrist-slaps, levying fines against the offending parties that will (hopefully) teach them a lesson about respecting their customers. Enforcement is additionally hindered by the fact that many diners most likely feel skittish about contacting a government agency with a complaint that "this fish made me shit my pants." Really, a customer's only recourse is to ask a vendor directly it if there are any side effects to eating this fish. The honest brokers will confirm that there are and recommend only eating escolar in small portions. Any establishment that serves larger than an eight-ounce portion is willfully putting anything you sit on in danger.

For those of you who'd like to try it yourselves, Aquagrill is currently serving escolar as part of its prix fixe Valentine's Day menu. Just beware that by night's end you might be removing your pants for other reasons than you expected.