Keriorrhoea--the passage of oil per rectum--after ingestion of marine wax esters.

Lepidocybium flavobrunneum, a marine fish of the snake mackerel family, is sometimes sold under the category of 'butterfish'. Ingestion of this fish was observed to be followed by the passage of oil per rectum. The fish was found to contain 23% by weight of lipid and analysis of this, and of the oil passed per rectum, showed that it consisted of wax esters. The high proportion of wax esters in the flesh of the fish, their resistance to digestive enzymes, and their low melting point, result in pooling in the rectum of significant volumes of oil, the lubricant quality of which causes frequent calls to stool. The symptomatology is therefore quite characteristic, but with the quantities normally ingested the condition appears to be harmless, despite reports of toxic effects in experimental animals.