Ricardo A. Caicedo, MD Pediatric Gastroenterology University of Florida Diarrhea Increase in frequency and water content of stools MECHANISM Examples MALABSORPTION Celiac disease, Rotavirus OSMOTIC Lactase deficiency SECRETORY Cholera, C. difficile toxin HYPERMOTILITY IBS INFLAMMATORY IBD, Shigella Acute Diarrhea • Infection – Viral gastroenteritis • Rotavirus • Enterovirus, adenovirus • Norwalk virus – Bacterial enterocolitis • • • • Shigella, Salmonella Yersinia, Campylobacter E.coli – enteroinvasive C. difficile – Foodborne • S.aureus, Bacillus cereus • E. coli – enterotoxigenic – Other: UTI, OM • Inflammatory – Hemolytic Uremic Syndrome (HUS) – Henoch-Schonlein Purpura (HSP) • Anatomic – Intussusception – Appendicitis • Toxic Ingestion – Iron, mercury, lead • Other – Antibiotic-induced – Hyperconcentrated infant formula – Overfeeding infants Chronic Diarrhea • Infection – parasitic – Giardia lamblia – Entamoeba histolytica – Cryptosporidium parvum • Inflammatory – Milk protein intolerance – Food allergy – IBD Duration > 2 weeks • Malabsorption – Celiac disease – Cystic fibrosis – Bacterial overgrowth • Osmotic – Lactase deficiency • Primary • Secondary post-infectious – Excessive fructose intake – Laxative overuse Parasitic Organism Sources Duration Giardia Entamoeba Cryptosporidium Fecal-oral, water supplies 2 wks – years Same Weeks Same, plus petting zoos, swimming pools 2 wks Cyclospora Water, unpasteurized apple 1wk-1month cider Isospora Strongyloides Fecal-oral, water > 2 wks Fecal-oral Appalachia same Blastocystis hominis Pathogenic? Keating J (2005) Pediatr Rev 26: 5-13. Tan KS et al (2002) Int J Parasitol 32: 789-804 Giardiasis • Presentation – Watery, foul stools – Abdominal distention • Bloating, flatulence – – – – Crampy abdominal pain Malaise, weakness Nausea/vomiting Anorexia, wt loss • Risk factors – – – – Well water Daycare Public pools, summer camp Immunodeficiency • Diagnosis – Stool antigen test • Greater sensitivity than O+P • Simpler than duodenal bx – Often overlooked • Fever, WBC, eosinophilia rare • Natural history – Most become asx by 6 wks – Frequent re-infx (up to 35%) – Few develop prolonged diarrhea with wt loss and growth failure • Treatment – Flagyl 15 mg/kg/d X 10 d • Albendazole, furazolidone • Asx carriers usually not treated Prolonged Viral/Bacterial Diarrheas Agent Sources Adenovirus, Rotavirus, CMV Duration Avg. 11 d Months in immunodeficient C. difficile Abx, nosocomial Campylobacter Raw poultry, unpasteurized 5 d - weeks milk, contaminated water Salmonella Poultry, fecal-oral Months in infants Yersinia Raw pig intestines, fecaloral 3 wks -3 months Aeromonas Untreated water 1 wk – 1 yr Keating J (2005) Pediatr Rev 26: 5-13. Relapses in 10% of cases Prolonged Diarrhea in Infants • Prolonged/recurrent diarrhea • Failure to gain weight Sucrase-isomaltase deficiency “Slick Gut” Syndrome – Intractable diarrhea of infancy, postenteritis enteropathy – Metabolic acidosis – Treatment due to malrotation OTHER: Immunodeficiency CF VIPoma Abetalipoproteinemia Celiac disease Congenital intestinal lymphangiectasia • Initial lactose-free, sucrosefree formula • Elemental formula • TPN = diagnosable by SB bx Small bowel biopsy Tufting enteropathy No effective tx Congenital lymphangiectasia Protein losing enteropathy Villous clubbing Subepithelial bleb MCT and high protein diet Microvillus inclusion disease Neonatal Apical membrane autophagocytosis Consanguinity TPN-dependence, SB Transplant Toddler’s diarrhea • Chronic nonspecific diarrhea of childhood • Symptoms – Explosive loose stools – Contain food particles – Frequent stools, decline as day goes on • Management – Verify normal growth and absence of red flags • Blood in stool, persistent fever, anemia – Exclude celiac disease (tTG) and Giardia – Trial of dietary modification • Restrict fructose and/or lactose Diarrhea in older children • OSMOTIC – Lactase deficiency • Primary – African, Asian, Hispanic • Secondary – Postenteritis – Laxative overuse/Poisoning • INFLAMMATORY – Infectious – IBD • FUNCTIONAL/hypermotility – IBS – CNSD (Toddler’s) • MALABSORPTIVE – – – – – – – Celiac disease CF Pancreatic insufficiency steatorrhea Chronic cholestasis Bacterial overgrowth Zinc deficiency Intestinal lymphangiectasia • Cong. Heart Dz (Fontan physiol) • Tumor or radiation • SECRETORY Secretory diarrheas • • • • Voluminous watery Persists despite bowel rest Massive efflux of fluid/salt Stool electrolyte content similar to serum • WDHA syndrome – Watery diarrhea – Hypokalemia – Alkalosis • DIFFERENTIAL DX – – – – – Cholera C. difficile Severe mucosal injury Short bowel syndrome Secretory tumors • • • • • • Carcinoid Gastrinoma Ganglioneuroma Neuroblastoma Pheochromocytoma VIPoma Zinc deficiency • Acrodermatitis enteropathica – – – – Perineal and perioral rash Chronic diarrhea & undernutrition Low serum Zn and alk phos Primary • Rare, recessive, mutation in Zn transporter – Secondary • • • • • • CF Crohn’s Anorexia nervosa Dialysis Chronic TPN Exclusively breastfed preterms – Tx = longterm Zn supplementation Immunodeficiency CONDITION Immunosuppression DIARRHEA CMV colitis, Cryptosporidium, Isospora, Entamoeba, Microspora, Cyclospora HIV Cryptosporidium, Giardia, +/- VIP-oma SCID CGD Wiskott CVID Hyper IgM Selective IgA deficiency MHC II deficiency 50% have protracted diarrhea in infancy Crohn-like colitis early in life IBD-like early in life Campy, Giardia 50% have chronic diarrhea Increased risk of chronic giardiasis Death in infancy due to severe malabsorption Approach • Impact of diarrhea – How is the infant/child growing? – How is symptom affecting child’s life? • Mechanism of diarrhea – Description of stool • Blood? Oily? Food particles? • Frequency – Diet and exposures • Complete physical exam – Attention to skin, LN, spleen • Screening and diagnostic tests Screening tests • BLOOD – – – – – – – Electrolytes Total protein/albumin Liver tests CBC ESR Celiac serology (tTG) Vitamin levels • B12, FA, Fe • A, D, E • STOOL – – – – – – – – – Guaiac pH and reducing substances Spot fat stain Gram stain/Culture Giardia Ag O+P C. diff toxin Osmolarity Electrolytes Secretory vs. Osmotic Osmotic Gap: 290 – {2 ([Na+] +[ K+])} Stool Na > 70 Osmotic Gap < 100 Persists while NPO Stool Na < 70 Osmotic Gap > 100 Decreases when NPO Malabsorption studies • FAT • CARBOHYDRATE – Spot fecal fat stain – Quantitative 72 hr • Total excretion > 5g fat/24 h • Coefficient of absorption = (fat ingested – excreted)/ingested X 100% • PROTEIN – Fecal A1AT • Suggests mucosal disorder such as celiac disease – Stool pH < 5.5 – Reducing sugars • Lactose, maltose, fructose, galactose – Breath hydrogen test • H2 produced by bacterial fermentation of undigested CHO • Rise in H2 > 20 ppm above baseline: malabs. • Elevated baseline or ∆20 ppm w/in 30 min: overgrowth Barney Beagle Thank You!