Hello - thanks for asking your question.
Before attributing the discomfort to IBS, make sure that it isn't anything more serious first.
Diseases associated with constipation include neurologic and metabolic disorders, obstructing lesions of the gastrointestinal tract, including colorectal cancer, and endocrine disorders such as diabetes mellitus. Other abnormalities leading to impairment of defecation include aganglionosis (Hirschsprung's disease) and acquired functional outlet disorder (pelvic floor dyssynergia). In addition, patients with irritable bowel syndrome often complain of periods of constipation, which may alternate with periods of diarrhea or normal bowel function.
Endoscopy (either a flexible sigmoidoscopy or colonoscopy) should be considered to make sure there are no lesions causing the constipation. Colonic marker studies, defecography, and anorectal manometry may be considered to evaluate for any conditions causing abnormal transit or pelvic flood dysfunction.
Finally, irritable bowel is also possible. This is mostly a diagnosis of exclusion - meaning that all the other tests should be negative before settling on this diagnosis. There are medications such as Zelnorm which specifically targets constipation-predominant IBS. This should be discussed with a gastroenterologist.
Followup with your personal physician is essential.
This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.
Thanks,
Kevin, M.D.