Treatment includes addition of more fiber in your diet,cessation of smoking and taking stress,antispasmodic medicines,antidiarrheal medicines,antidepressants and new medicines like Alosetron (Lotronex) and
Tegaserod (Zelnorm).
You can read more about this from the following website and discuss it with your doctor:
http://www.emedicinehealth.com/irritable_bowel_syndrome/article_em.htm
Hope it helps.Take care and pls do keep me posted on how you are doing.