Diosgenin (2.25 g) was coated onto cellulose and dosed daily to a lamb for 12 d by intraruminal intubation. Upon completion of dosing, samples of gut contents and internal organs were subjected to chemical analysis and histological examination. No clinical signs, changes in serum chemistry, or microscopic organ changes were observed. GC-MS analyses showed that in the rumen diosgenin was metabolised to free and, to a lesser extent, conjugated derivatives of tigogenin, smilagenin and epismilagenin. Reduction of diosgenin to smilagenin and tigogenin, and epimerization of smilagenin to epismilagenin, appeared to continue in the duodenum, ileum and jejunum. Deconjugation and the epimerization of smilagenin to epismilagenin appeared to continue in the cecum and colon. Epismilagenin was the dominant conjugated sapogenin constituent identified in a bile sample.