Painful or Mild-Pain Constipation? A Clinically Useful Alternative to Classification as Irritable Bowel Syndrome with Constipation Versus Functional Constipation.

PURPOSE: Abdominal pain is not used to characterize constipated patients. This study aimed to compare clinical, psychological, and physiological features in patients with IBS-constipation (IBS-C) with those in patients with functional constipation (FC) according to the intensity of abdominal pain. METHODS: All patients filled a standard Rome III questionnaire. In addition, they indicated the intensity of constipation, diarrhea, bloating, and abdominal pain on a 10-point Likert scale, and their stool form with the Bristol Stool Form Scale. Anxiety and depression were assessed with the Beck Depression Inventory and the State-Trait Anxiety Inventory. Physiological evaluation included anorectal manometry and total and segmental colonic transit time. MAIN RESULTS: A total of 546 consecutive patients, 245 with IBS-C and 301 with FC, were included. Painful constipation (PFC) was found by cluster analysis and subsequently defined as having a value over four on the Likert scale for abdominal pain. PFC was found in 67% of IBS-C patients and in 22% of FC patients. PFC patients have digestive disorders with greater frequency and report higher levels of constipation and bloating, despite similar stool form. They have higher scores of depression, state and trait anxiety, and shorter terminal transit time than mild-pain constipated patients. Compared to IBS-C patients, PFC patients report higher levels of abdominal pain (P < 0.001). Psychological and physiological parameters were similar in PFC and IBS-C patients. CONCLUSION: Painful constipation and mild-pain constipation could be an alternative way to identify constipated patients than using the diagnosis of IBS-C and FC for clinical evaluation and drug studies.