Pocket Pediatrics: The Massachusetts General Hospital for Children Handbook of Pediatrics (Pocket Notebook Series), 2 Ed.


Definition (Pediatr Rev 2005;26:5)

• No consistent duration separates chronic from acute; generally >2 wk to 1 mo

Etiology (Curr Opin Gastroenterol 2011;27:19; Pediatr Rev 2005;26:5)

• Studies demonstrate persistent/chronic diarrhea account for 5–18% of diarrheal cases

• Congenital: Rare, generally presents w/i 1st yr of life if not sooner

• Structural abnormality: Chronic SBO or malrotation. Dx w/ radiology

• Microvillus inclusion disease: Presents on DOL 1 w/ large volume watery diarrhea (continues when NPO); no cure, need TPN/PPN, death in infancy

• Acquired: More common, higher risk w/ immune compromise

• Viral diarrhea: Mean duration is 6 d in absence of immune dysfunction

• Bacterial diarrhea: Mean duration is 14 d but some agents much longer

• Nontyphoid Salmonella in neonates can cause several mos of diarrhea

• Exposure to untreated water, shellfish: Aeromonas spp, Plesiomonas

• Parasitic: Immunocompetent or -compromised, often occult fecal exposure

• Giardia is most common in US, 2/2 exposure to feces

• Associated sx: Malaise, flatulence, abd distention, only  w/ vomiting

• ∼¼ w/ intermittent symptoms; avg duration in immunocompetent ½ mo

• Small % immunocompetent get prolonged sx, FTT, stunting up to 2+ yr

• Cryptosporidium: 2+ wks. Rarely found on O&P, need fecal antigen test, generally assoc w/ immunosupressed

• Cyclospora: Generally w/ immunocompromised; classically unpasteurized apple cider or imported raspberries

• Immune mediated: Food allergy or celiac disease; + exposure and IgE or Ab testing

• Immunodeficiency states often present w/ chronic diarrhea 2/2 chronic infection w/ one of the above agents, CVID, SCID, HIV, X-linked Bruton agammaglobulinemia, CGD (looks like Crohn’s), Wiskott–Aldrich (IBD-like)

• Complication of acute gastroenteritis seen mostly in developing world; generally due to resulting malnutrition and micronutrient deficiencies

Diagnostic Evaluation


• Highly dependent on etiology; see specific etiology subheadings where included