We propose to recruit our cohort of patients from the King Fahad Medical City in Riyadh (largest tertiary care hospital of Saudi MOH with wide open referral system), over one year between July 2010 and July of 2011. Fifty participants with each of the focus conditions (IBS, UC, CD, CRC) will be compared to fifty participants with no GI complaints and have a normal colonic mucosa (by endoscopic and histological examination).