The present invention provides a 13C-labeled oligosaccharide or polysaccharide
or a salt thereof excluding U-13C-maltose, 13C-starch, 1-13C-maltotetraose
and 1-13C-amylose; a derivative of the 13C-labeled oligosaccharide
or polysaccharide or salt thereof; a 13C-labeled inclusion complex or
a salt thereof, which comprises a cyclodextrin or a modified derivative thereof
as a host molecule; a 13C- or 14C-labeled fluorescein ester
compound or a salt thereof; and a diagnostic agents for pancreatic exocrine function
comprising these compounds 13C- or 14C-labeled.