Shot in the gut.

A mystifying case of lead poisoning, which may have lasted more than a decade, ultimately resolved itself--but not before teaching two Swedish physicians how difficult it can be diagnose its cause.

In January 2002, Per Gustavsson of the Karolinska Institute in Stockholm and Lars Gerhardsson of Sahlgrenska University Hospital in Goteborg saw a 45-year-old patient with substantially elevated lead in her blood. She complained of malaise and fatigue. A decade earlier, similar symptoms had been treated with lead-binding drugs.

After 9 months of searching fruitlessly for a dietary or environmental cause, Gustavsson and Gerhardsson X-rayed the woman's abdomen and discovered a dense, round object in her colon. Soon afterward, during a diarrheal infection, the woman expelled a 6-millimeter lead pellet. Her blood-lead concentration then began to fall, and her symptoms gradually disappeared.

The patient may have unknowingly consumed the pellet while eating game meat, the researchers say.

While the ease is unusual, similar cases have occurred, the researchers note in the April Environmental Health Perspectives. For example, a 1986 report described a 30-year-old hunter who had 29 lead pellets in his colon and appendix.