​Differential diagnosis of causes of intestinal bacterial overgrowth

​Differential diagnosis of causes of intestinal bacterial overgrowth 
-gastric achlorhydria 
-gastrocolic or coloenteric fistula such as Crohn’s disease, surgical resection and malignancy 
-small intestine motility disorder such as scleroderma, diabetic enteropathy, chronic intestinal pseudo obstruction
-anatomic abnormality of small intestine with stagnation due to afferent limb of Billroth II  gastrojejunostomy, small intestine diverticular, obstruction, blind loop, radiation enteritis 
-AIDS and chronic pancreatitis