The diagnostic value of colonoscopy for chronic diarrhea

Abstract

Objective To evaluate the diagnostic value of colonoscopy for patients with chronic di- arrhea. Methods Data of 2449 patients with chronic diarrhea who underwent colonoscopy from January, 1999 to December, 2008 were reviewed. A total of 2110 patients who underwent colonoscopy screening for health checkup during the same period were used as controls. The rates of clinic-relevant abnormal endoscop- ic findings and negative finding were compared between two groups. Results Lesions with clinic signifi- cance were found in 44. 1% of patients with chronic diarrhea （1080/2449） and in 41.7% of controls （870/2110, X2 = 2. 756, P = 0. 097）. Compared with controls, incidence of non-IBD and noninfectious co- litis （X2 =58. 578, P 〈 0. 001 ）, IBD （X2 = 59. 609, P 〈 0. 001 ）, malignant tumor （X2 = 21. 649, P 〈 0. 001 ）, terminal ileitis （X2 =6. 275, P =0. 012）, infectious colitis （X2 = 17.019, P 〈0. 001 ）, intestinal tuberculosis （X2 = 7. 021, P = 0. 008 ）, melanosis coli （X2 = 6. 040, P = 0. 014 ） and parasitic infection （X2 = 4. 245, P = O. 039 ） were all significantly higher in patients with chronic diarrhea. However, inci- dences of adenomatous polyps （X2 = 14. 124, P 〈 0. 001 ） , non-adenomatous polyps 0（2 = 33. 427, P 〈 0. 001 ） and diverticular disease （X2 = 9. 921, P = 0. 002 ） were significantly higher in the control group. There was no significant difference in incidences of the benign tumor （X2 = 1. 627, P = O. 202 ） and an- giodysplasia （X2 = 0. 231, P = 0. 631 ） between the two groups. The overall screening rate of colonic polyps, divertieulosis, and vascular lesions was 37.3% in chronic diarrhea group. Conclusion Colonic polyps, di- verticulitis, benign tumors and angiodysplasia may not be the causes of chronic diarrhea. Etiology of more than 1/3 patients with chronic diarrhea remains unknown after eolonoscopy. Key words: Chronic diarrhea; Colonoscopy; Organic colonic lesions