Initial evaluation of chronic diarrhea in children >6 months old without warning signs

tTg: tissue transglutaminase; CBC: complete blood count; IBD: inflammatory bowel disease; C. difficile: Clostridioides difficile; S. typhi: Salmonella typhi; IBS-D: diarrhea-predominant irritable bowel syndrome; FODMAP: fermentable oligosaccharides, disaccharides, monosaccharides, and polyols.
* For details on history, physical examination, and causes, refer to UpToDate topic and tables on evaluation of chronic diarrhea in children.
¶ Clinical signs/symptoms suggesting a possible immunodeficiency include a history of infections and persistent or recurrent infectious diarrhea.
Δ Inflammatory diarrhea is likely if gross rectal bleeding is present and/or if stool calprotectin or lactoferrin are elevated. Refer to algorithm on inflammatory diarrhea in children.
◊ Drugs that can cause diarrhea include antibiotics (eg, amoxicillin-clavulanate) and a varity of other drugs. Refer to UpToDate table on medications associated with diarrhea.
§ Diet-induced diarrhea refers to diarrhea that is caused or exacerbated by osmotic load in the intestinal lumen. The primary cause may be a specific dietary component (eg, excessive fructose or sorbitol), impaired absorption of nutrients (eg, primary lactase nonpersistence or postinfectious diarrhea), or food protein-induced intestinal injury (allergic proctocolitis of infancy or other food allergy).
¥ Functional diarrhea in young children is sometimes called "toddler's diarrhea." In older children, functional diarrhea is a form of IBS-D.
‡ Dietary changes that are sometimes helpful for functional diarrhea include reducing fructose or sorbitol consumption (eg, fruit juice). In older children with IBS-D, dietary changes may include lactose or sorbitol restriction or a low-FODMAP diet.