摘要:The faecal concentrations of urobilinogen, active trypsin and fusiform-shaped bacteria were measured after caecectomy of specific pathogen-free mice. Caecectomy resulted in reduced faecal concentrations of urobilinogen and increased faecal levels of active trypsin. Microscopical examination of the faecal pellets revealed a reduced number of fusiforms after caecectomy. Our results provide direct evidence that the caecum is important for degradation of tryptic activity and formation of urobilinogen and that fusiform-shaped bacteria may be involved in this process.Keywords: caecectomy, urobilinogen, trypsin.