Diarrhea

1. Chronic Diarrhea Ricardo A. Caicedo, MD Pediatric Gastroenterology University of Florida

2. Diarrhea Increase in frequency and water content of stools

3. 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 Acute Diarrhea

4. Infection – parasitic Giardia lamblia Entamoeba histolytica Cryptosporidium parvum Inflammatory Milk protein intolerance Food allergy IBD Malabsorption Celiac disease Cystic fibrosis Bacterial overgrowth Osmotic Lactase deficiency Primary Secondary post-infectious Excessive fructose intake Laxative overuse Chronic Diarrhea Duration > 2 weeks

5. Parasitic Tan KS et al (2002) Int J Parasitol 32: 789-804 Keating J (2005) Pediatr Rev 26: 5-13.

6. 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 Giardiasis

7. Prolonged Viral/Bacterial Diarrheas

8. Prolonged Diarrhea in Infants • Prolonged/recurrent diarrhea • Failure to gain weight • Intractable diarrhea of infancy, postenteritis enteropathy • Metabolic acidosis • Treatment • Initial lactose-free, sucrose-free formula • Elemental formula • TPN “Slick Gut” Syndrome Sucrase-isomaltase deficiency due to malrotation OTHER: Immunodeficiency CF VIPoma Abetalipoproteinemia Celiac disease Congenital intestinal lymphangiectasia = diagnosable by SB bx

9. 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

11. 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

12. 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 Chronic cholestasis Bacterial overgrowth Zinc deficiency Intestinal lymphangiectasia Cong. Heart Dz (Fontan physiol) Tumor or radiation SECRETORY Diarrhea in older children steatorrhea

13. 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 Secretory diarrheas

14. 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

15. Immunodeficiency

16. 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

17. 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 Screening tests

18. Secretory vs. Osmotic Osmotic Gap: 290 – {2 ([Na+] +[ K+])} Stool Na > 70 Osmotic Gap < 100 Stool Na < 70 Osmotic Gap > 100 Persists while NPO Decreases when NPO

19. FAT Spot fecal fat stain Quantitative 72 hr Total excretion > 5g fat/24 h Coefficient of absorption = (fat ingested – excreted)/ingested X 100% PROTEIN Fecal alpha-1-antitrypsin (A1AT) Suggests mucosal disorder such as celiac disease CARBOHYDRATE Stool pH < 5.5 Reducing sugars Lactose, maltose, fructose, galactose Breath hydrogen (H2) test H2 produced by bacterial fermentation of undigested CHO Rise in H2 > 20 ppm above baseline: malabs. Elevated baseline or Δ20 ppm w/in 30 min: overgrowth Malabsorption studies