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