A 33-year-old previously healthy man was admitted to the hospital with a 6-day history of diffuse abdominal pain and constipation. He was afebrile, looked unwell with a pale skin and displayed an elevated blood pressure. He had no peritoneal sign, and bowel sounds were normal. Blood tests were remarkable for a hematocrit of 26 % and mean cell volume of 83 fl, bilirubin levels were slightly elevated. Abdominal radiographs, abdominal ultrasound and computed tomography showed stool throughout the colon with a non-specific bowel gas pattern. Moreover, colonoscopy and gastroscopy provided no information on the underlying cause of the patient's severe pain. He was treated with fluids and spasmolytic drugs until the result of the urinary porphyrin level was received, which showed an elevated concentration of 1608 microg/d. Consequently, the plasma lead concentration was determined showing an elevated level of 92.3 microg/d. The examination of blood slides revealed erythrocytes with basophile stippling. On physical examination, a bluish discoloration could be seen along the gums. After starting the detoxication therapy with DMPS - 1800 mg p. o. for the first two days followed by 600 mg DMPS daily - the complaints disappeared. In spite of an extensive anamnestic exploration the source of the lead intoxication could not be found until now.