Distal Location of Colonic Markers Did Not Predict Outlet Obstruction

Patients with severe constipation who have undergone structural examination (e.g., colonoscopy) sometimes undergo functional testing. This typically includes measures of colonic transit and outlet function, and severely constipated patients may have colonic inertia, outlet obstruction, or both abnormalities. Traditionally, in radiopaque marker studies of these patients, results showing delay with markers spread throughout the colon were thought to be more consistent with colonic inertia, whereas markers clustered in the rectosigmoid were thought to be more suggestive of outlet obstruction. However, few data support this assumption.

To assess whether rectosigmoid location of markers is associated with outlet obstruction, investigators retrosp…