Regional colonic transit pattern does not conclusively identify evacuation disorders in constipated patients with delayed colonic transit

Background/Aims After exclusion of structural diseases, chronic constipation may be associated with normal or slow transit or rectal evacuation disorders. We evaluated: (1) clinical features and anorectal function, (2) difference of regional colonic transit according to the presence or absence of evacuation disorders, and (3) association of colonic transit with gender in patients with objectively slow colonic transit. Methods We reviewed electronic medical records of 1553 patients with constipation seen by one gastroenterologist from 1994-2015 at a tertiary medical center. We identified patients with slow colonic transit using scintigraphy. Evacuation disorders were identified on clinical examination or anorectal manometry. Colonic compliance and tone were measured in 29 patients. Statistical analysis was by the Mann-Whitney rank sum test. Results Of the 207 patients (155 females, mean age 41.3 ± 15.3 [SD] years), 113 had evacuation disorders (ED+ve) and 94 did not (ED-ve). There were no significant differences in colonic transit or gastric emptying between ED+ve or ED-ve; similarly, colonic compliance, tone and responses to neostigmine were not different in ED+ve and ED-ve. Conversely, there were significant differences by gender in patients with slow colonic transit: colonic transit, small bowel transit, and gastric emptying (all P < 0.005). Conclusions Delayed colonic transit does not exclude evacuation disorders in chronic constipation. In chronic constipation and objectively slow colonic transit, females had slower gastric, small bowel, and colonic transit than males.