Objective        To investigate the anorectal manometry in different types of constipation and its significance in the diagnosis of the disease.       Methods        Clinical data of 163 out- and in-patients with constipation in our department from March 2010 to June 2013 were retrospectively collected. They were divided into colonic slow transit constipation group (

n

=46)

outlet obstruction constipation (

n

=93)

and mixed constipation (

n

=24). Anot

her 30 healthy individuals served as normal control group. Anorectal manometry was carried out in controls and patients with chronic constipation. The rectal first sensation

first defecation sensation

maximum tolerable volume

anal resting pressure

squeeze pressure

coughing pressure and defecation pressure were determined.       Results        No difference was found in rectal first sensation and first defecation sensation between the patients and normal controls

while maximum tolerable volume was significantly higher in the former than the later group (

P

<

0.05). The anal resting pressure and squeeze pressure of patients with constipation were lower in the patients than controls (

P

<

0.05). The anal resting pressure

squeeze pressure

coughing pressure and defecation pressure were lower of patients with slow transit constipation than in controls and outlet obstructive constipation patients

while the defecation pressure of outlet obstructive constipation patients was increased significantly (

P

<

0.05).       Conclusion        Patients with different types of constipation have different anorectal manometry

suggesting that constipation patients having abnormalities in anorectal dynamics and sensory function.