The colon transit time (CTT) of the twenty six patients was measured using radio-opaque markers for the ascending (aCTT), descending (dCTT), rectosigmoid (rs. CTT) colons as well as for the entire colon (tCTT). After 4 days, the spinal processes and imaginary lines from the 5th lumbar vertebra to the left iliac crest and pelvic outlet served as landmarks.