Renal excretion of contrast medium after endoscopic retrograde investigations

Endoscopic retrograde investigations are often performed as diagnostic procedures. The investigation of urine after such procedures in 21 patients has shown that appreciable amounts of contrast medium can be excreted renally. No such excretion could be shown when the contrast medium was injected into the gut lumen. The fact that contrast medium can be absorbed into the liver the pancreas during endoscopic retrograde procedures should influence the decision to perform these studies in patients with known allergies.