Poulos C, Riewpaiboon A, Stewart JF, Clemens J, Guh S, Agtini M, Anh DD, Baiqing D, Bhutta Z, Sur D, Whittington D. Cost of illness due to typhoid fever in five Asian countries. Trop Med Int Health. 2011 Mar 1;16(3):314-23.
Candrilli SD, Davis KL, Iyer S. Impact of constipation on opioid use patterns, health care resource utilization, and costs in cancer patients on opioid therapy. J Pain Palliat Care Pharmacother. 2009 Sep 1;23(3):231-41.
Cole JA, Rothman KJ, Cabral HJ, Zhang Y, Farraye FA. Incidence of IBS in a cohort of people with asthma. Dig Dis Sci. 2007 Feb 28;52(2):329-35.