Keriorrhea: Causes and Clinical Presentation

Keriorrhea is a gastrointestinal condition characterized by the production of greasy, orange-colored stools. It is primarily caused by the consumption of fish species containing high concentrations of indigestible wax esters, most notably escolar (Lepidocybium flavobrunneum) and oilfish (Ruvettus pretiosus).

Pathophysiology

The condition results from the human body's inability to digest the wax esters present in the flesh of these specific fish. These esters, which are essentially liquid waxes, pass through the digestive tract largely unchanged. Their presence acts as a lubricant, leading to the rapid passage of stool and the characteristic oily, orange-tinted discharge. Unlike many other forms of foodborne illness, keriorrhea is typically not associated with abdominal pain, cramping, or systemic infection, as it is a mechanical rather than a pathogenic process.

Clinical Presentation

Symptoms of keriorrhea often manifest within a few hours of ingestion, with onset typically occurring between 30 minutes and several days after consumption. The primary clinical features include:

• Profuse, oily diarrhea
• Orange-colored stool or leakage
• Rectal incontinence
• Flatulence

The condition is generally self-limiting, with symptoms typically subsiding within a few days. Because the symptoms can be distressing and involve involuntary leakage, the condition is sometimes colloquially referred to as "oily anal leakage."

Epidemiology and Regulation

Outbreaks of keriorrhea are frequently linked to the mislabeling of escolar or oilfish as more expensive or commonly consumed species, such as sea bass, cod, or white tuna. Due to the high incidence of these reactions, several countries—including Italy, Japan, and the Republic of Korea—have implemented bans or strict regulations regarding the sale and consumption of these fish species. Other regions, including Australia, Canada, the United States, and parts of the European Union, have issued guidance for the food industry regarding the labeling and sale of these products to prevent accidental consumption.