Objective        To investigate the value and significance of colonic transit tests in the diagnosis of slow transit constipation.       Methods        Clinical data and images of 414 peoples who underwent colonic transit tests in our department from September 2007 to May 2013 were collected in this study. They were 87 males and 327 females

with a mean age of 45.9 years

ranging from 13 to 82. Their manifestations included reduced stool frequency

and decreased desire to defecate

accompanied with dry stool

and laborious defecation. Their course of disease ranged from 3 to 37 years

with a mean time of 1

0.7 years. They all conformed to the diagnostic criteria of Rome III. After the patients taking 20 capsules containing mark

the distribution of mark were observed in 24

48 and 72 h after taking by abdominal vertical radiography.        Results        These 414 peoples were divided into 2 groups according to the numbers of marks in the colorectum after 72 h

that is

197 peoples having more than or equal 5 marks

and 217 peoples having not. There were significantly difference in each time point between the 2 groups (

P

<

0.05).       Conclusion        This test shows the difference of colon transportation function

but these are different ideas on whether the test can be used as the standards for the diagnosis of STC. More data are needed to obtain further results. And these tests can be done in one people for several times

to make the result much closer to the truth.