Comparison of 14C-labelled polyethylene glycol (PEG) with carrier PEG and 14C-PEG alone as a volume indicator in the human jejunum.

14C-labelled polyethylene glycol (PEG) (5 muCi/l) was used as a non-absorbable marker in human jejunum both with and without carrier PEG (5 g/l). Calculation of net water flux was virtually identical whether or not the carrier PEG was included in the perfusion solution. 14C-PEG alone is a satisfactory non-absorbable marker for perfusion studies in the human jejunum.