Recovery of Creatinine After Ingestion and After Intravenous Injection in Man

In a patient with an ileal fistula it was shown that about 25% of ingested creatinine was expelled unabsorbed from the fistula. The amount of creatinine excreted in the urine was equal to the amount absorbed. The evidence suggests that, in oral experiments, no creatinine is absorbed by the large intestine. When injected intravenously, creatinine is virtually all excreted in the urine. These results are at variance with the hypothesis of creatinine transformation in the human body.