Prevalence of microscopic colitis in patients with diarrhea of unknown etiology in Turkey

Table 1 Inclusion criteria for study

Inclusion criteria
Diarrhea without blood (> 3 mo)
Normal stool microscopy
No growth in stool culture
Normal D-Xylose absorption test
Normal biochemical profile
Normal thyroid tests, normal serum gastrin
Negative antigliadin antibodies (IgA, IgG)
Negative Clostridium difficile toxins (A, B)
Negative HIV test
Normal urine 5-HIAA
Normal upper GI endoscopy
Normal abdominal US
Normal small bowel radiology
Normal duodenal biopsy
Normal colonoscopy including terminal ileum

Table 2 Histopathologic criteria for diagnosis of lymphocytic colitis and collagenous colitis

	Histopathologic criteria
Lymphocytic colitis	Chronic inflammatory infiltration in lamina propria
	Increased IELs
	Superficial epithelial degeneration and increased mitosis in crypts
	IELs/100 intercryptal epithelial cell > 20/100
Collagenous colitis	A diffusely distributed and thickened sube-pithelial collagen band > 10 &mgr;m
	Chronic inflammatory infiltration in lamina propria