1. Epidemiology of constipation in North America: a systematic review;Higgins;Am J Gastroenterol,2004
2. AGA technical review on constipation;Locke;Gastroenterology,2000
3. Functional bowel disorders;Longstreth;Gastroenterology,2006
4. Healthcare utilization and costs associated with constipation and co-occurring irritable bowel syndrome and constipation compared to matched controls in a large managed care population;Mitra;Gastroenterology,2007
5. The annual cost of constipation in the U.S. ambulatory and inpatient care settings;Martin;Gastroenterology,2005