Rectal sensitivity in cases of constipation with different subtypes

Objective To investigate the differences of the rectal sensitivity between functional constipation (FC) and constipation-predominant IBS (C-IBS).Methods The rectal sensitivities in patients with FC,C-IBS and healthy controls were tested by a computerized Barostat with a 500ml polyethylene bag,and the pressure was controlled by rapid phasic distention.Results The pressures of urgency and pain in FC patients (22.61±10.03 mmHg;32.11±9.73 mmHg) were significantly higher than those in controls (14.64±4.20 mmHg; 25.18±5.38 mmHg).However,comparing with healthy volunteers,the first perception in C-IBS patients was significantly decreased (5.58±3.48mmHg vs.8.81±5.90mmHg).The pressures of all sensation were significant decreased in C-IBS patients,compared with FC.There is no difference in rectal resting pressure,anal resting pressure and anal squeeze pressure among the three groups.Conclusion Rectal hyposensitivity is an important pathogenesis of FC,hypersensitivity is popular in C-IBS.