Rectal function and bowel habit in irritable bowel syndrome

OBJECTIVES: Rectal compliance may influence rectal perception, but their functional implications remain incompletely understood. Our aim was to determine whether rectal function is related to bowel habit in the irritable bowel syndrome. METHODS: The responses to fixed tension rectal distension applied by means of a tensostat were compared among constipation-predominant (n = 9), diarrhea-predominant (n = 7), alternating habit (n = 11) irritable syndrome subgroups, and healthy controls (n = 15). RESULTS: Overall, patients had normal rectal compliance and increased perception, but compliance was lower in diarrhea-predominant as compared to constipation-predominant patients (6.7 ± 0.7 ml/mmHg vs. 9.9 ± 0.7 ml/mmHg, respectively; p < 0.05) and perception was higher (39 ± 6 g vs. 64 ± 9 g tolerance, respectively; p < 0.05). CONCLUSION: Distinctive tensosensitivity and compliance characterize rectal function in irritable bowel syndrome subgroups with different bowel habit.