Pediatric Gastroenterology and Hepatology 2024

Pediatric Gastroenterology and Hepatology 2024

Objectives

• Comprehensive review of RCPSC Training Objectives for Pediatric Gastroenterology
• Review of current evidence-based guidelines for managing RCPSC recognized "problems" common to the general pediatrician
• Preparation for MCQ/OSCE clinical scenarios

Malabsorption

• Failure to thrive and chronic diarrhea are common symptoms
• Causes: fat, protein, and carbohydrate malabsorption
• Biliary: bile emulsifies fat, pancreas: proteases, and duodenum: brush border hydrolysis
• Examples: CF, SDS, Crohn's disease, cholestasis
• Carbohydrate malabsorption: primary causes (enzyme deficiencies) and dietary causes (saturation of normal enzyme levels)

Celiac Disease

• Autoimmune enteropathy caused by systemically acting antibodies that are formed against gluten
• Screening: bloodwork +ve, but not sufficient alone; intestinal biopsy (villous atrophy) is required for diagnosis
• Typical symptoms: diarrhea, abdominal pain, and weight loss
• Associated conditions: type 1 diabetes, IgA deficiency, Down syndrome, Turner syndrome, and Williams syndrome
• Treatment: lifelong gluten-free diet

Inflammatory Bowel Disease

• Ulcerative colitis vs Crohn's disease: macroscopic and microscopic differences
• Presenting signs: diarrhea, abdominal pain, weight loss, and fatigue
• Major medication classes: INDUCE remission (tube feeds, corticosteroids, 5-ASA) and MAINTAIN remission (tube feeds, azathioprine, methotrexate, biologics)

Constipation

• 90% is functional, 10% is organic (hypercalcemia, hypothyroidism, lead poisoning, and Hirschsprung's disease)
• Chronic constipation: patient eventually develops megarectum and encopresis
• Laxatives by category: osmotic, stimulant, lubricant, and prokinetic
• Treatment: CLEANOUT à MAINTENANCE x4-6mo à SLOW WITHDRAWAL

Functional Gastrointestinal Disorders

• Childhood/adolescence FGID: nausea and vomiting disorders, abdominal migraine, functional abdominal pain, and defecation disorders
• Rumination syndrome, cyclic vomiting syndrome, and functional dyspepsia are examples of FGID### Functional Gastrointestinal Disorders in Infants and Toddlers
• Rumination Syndrome:
  • Repeated painless regurgitation and rechewing or expulsion of food that begins soon after ingestion of a meal
  • Does not occur during sleep
  • No retching
  • No organic explanation
  • Eating disorder must be ruled out
  • Responds to relaxation therapies, avoidance of behavioral reinforcement
• Cyclic Vomiting Syndrome:
  • At least 2 periods of intense nausea and hyperemesis or retching lasting hours to days (in the past 6 months)
  • Episodes are stereotypical
  • Return to usual state of health lasting weeks to months
  • Symptoms not attributable to other conditions
  • Family history of migraine

Abdominal Pain Disorders

• Irritable Bowel Syndrome:
  • Abdominal pain >4 times/month with at least 1 of the following symptoms:
    • Timing related to defecation
    • Change in frequency of stool
    • Change in form of stool
  • If patient experiences constipation (IBS-C), pain does not resolve with resolution of constipation
• Functional Abdominal Pain:
  • Very common
  • Occurs at least 4 times per month
  • Includes:
    • Episodic or continuous abdominal pain
    • Insufficient criteria for other FGID’s

Hepatology

• Approach to Hepatomegaly:
  • Inflammation (Hepatitis)
  • Storage Disorders (Glycogen, Lipid, Protein, Iron)
  • Infiltrative (Benign Liver Tumors, Malignant Liver Tumors, Disseminated Tumors)
  • Biliary Obstruction
  • Posthepatic Obstruction (Cardiac, Thrombus, Intrahepatic)
• Hyperbilirubinemia:
  • Prehepatic Causes:
    • Hemolytic (Extracellular: Sepsis/DIC, ABO/Rh, Sepsis/DIC, Intracellular: Membranopathy, Hemoglobinopathy)
    • Non-hemolytic (Physiologic, Gilbert’s Syndrome)
  • Hepatic Causes:
    • Inherited disorders (A1AT deficiency, Wilson’s Disease)
    • Acquired disorders (Viral Hepatitis, Autoimmune Hepatitis)
  • Posthepatic Causes:
    • Obstruction (Biliary Atresia, Choledochal Cyst)

Infectious Hepatitis

• Chronic Hepatitis B:
  • Defined as: HBsAg+ for >6 months, ALT >2X normal, and evidence of viral replication (HBeAg+ or HBV DNA >4 log if HBeAg-)
  • Treat with either IFN-a or lamivudine
  • 20-58% spontaneous conversion/clearance
• Surveillance Recommendations:
  • Measure ALT q6months in children >2yo
  • Measure HBeAg and HBeAb yearly in patients with normal ALT
  • Liver biopsy in children >2yo with elevated ALT
  • Examine for chronic liver disease
  • Immunize household members and patient against Hepatitis A
  • Alpha fetoprotein and ultrasound annually

Liver Transplantation

• Long-term Follow-up:
  • Neurodevelopmental Care
  • Medication Side Effects (Hypertension, Hyperglycemia, Seizure)
  • Secondary Graft Dysfunction
  • Infectious Disease (Common infections, Opportunistic infections)
  • Relapse of Primary Disease
  • Chronic Cellular (Graft) Rejection

Miscellaneous Hepatology Topics

• Non-Alcoholic Fatty Liver Disease (NAFLD):

  • Umbrella term
  • NAFLD: simple steatosis vs. NASH
  • Consider when BMI > 85%
  • Diagnosis of exclusion
  • Only effective treatments: weight loss, exercise

• Chronic Hepatitis in Pediatrics:

  • Differential Diagnosis:
    • Autoimmune Hepatitis
    • A1AT Deficiency
    • Wilson’s Disease
    • Celiac Disease
    • Infectious Hepatitis

• Pancreatitis:

  • Acute management:
    • Fluids (1.5-2x maintenance)
    • Enteral nutrition early (PO/GT à NJ à TPN)
    • Watch for complications (SIRS response)
  • Nutritional Considerations:
    • Early unrestricted diet should be started within 24-48 hours
    • NG > NJ as tolerated or combination EN/PN preferred over exclusive PN### Functional Gastrointestinal Disorders in Infants and Toddlers

• Defecatory Disorders:

  • Functional Constipation: • Occurs ≥1/week for ≥2 months • Not IBS • ≥2 symptoms in a child developmentally ≥4yo: • ≤2 bowel movements/week • ≥1 episode of fecal incontinence/week • Retentive posturing • Painful or hard bowel movements • Large fecal mass in rectum • Large diameter stools that may block toilet
  • Nonretentive Fecal Incontinence: • At least 1 month of episodes • ≥1/month defecation in places inappropriate to social context • No fecal retention • Not attributable to another condition

Complications of Acute Liver Failure

• Encephalopathy
• CVS effects
• Coagulopathy and hemorrhage
• Bone marrow failure
• Hypoglycemia
• Electrolyte/Acid-base imbalance
• Renal dysfunction
• Pancreatitis
• Ascites

Hepatitis B Treatments

• Interferon-a (IFN-a): • Cytokine • Side effects: neutropenia (39%), fever, myalgia, headaches, arthralgia, anorexia with weight loss, severe mood changes
• Nucleoside analogue (e.g., lamivudine): • Generally well tolerated • High mutation rate leading to resistance

Infectious Hepatitis

• Hepatitis C: • RNA virus • 0.2% of children 6-11yo and 0.4% of children 12-19yo • Spontaneous clearance in children: 20% in first 3 years of life, up to 50% by age 18 • Cirrhosis takes 10-20 years to develop, if ever • 6 genotypes • 1-3 most common in North America • 1 carries worst prognosis

Diagnosis

• Hepatitis C Ab (high false +ve)
• Confirm with Hepatitis C PCR and genotype
• In at-risk infants, continue screening until at least 18 months of age with two –ve Ab’s test in a row

Hepatology

• Cholelithiasis: • Types: Cholesterol, Brown Pigment, Black Pigment • Black Pigment: Hematologic origin (think coffee ground emesis)

Chronic Pancreatitis

• Causes: Toxic, Tropical, Metabolic, Idiopathic, Genetic, Autoimmune, Anatomic, Obstructive, Recurrent acute
• Investigations: MRCP, IgG4, genetics

Liver Pearls

• If AST > ALT, think EtOH, Myopathies, Renal syndromes, Hemolysis, Intestinal inflammation, Adenovirus infection
• If ALP is abnormally low, think Zinc deficiency
• If ALP low or normal + other enzymes high, think Wilson’s Disease
• Vitamin K-dependent Factors: Factor X, Factor IX, Factor VII, Factor II, Protein C, Protein S
• Factor VIII is the only coagulation factor not made in the liver

Managing Functional Constipation in Children

• Education about constipation important
• Breastfeeding variability (qFeed – q10d)
• Rome III Criteria for diagnosis (similar to Rome IV)
• Fecal disimpaction needed to initiate treatment (PEG, enemas, mineral oil, hospitalization)
• Investigations rarely necessary
• PEG3350 recommended for long-term Rx/ Stool diary, fiber intake
• Regular followup needed
• Referral to Pediatric GI for refractory or organic pathology

Position Statement: Energy and Sports Drinks in Children and Adolescents

• Not recommended: contributes to obesity, mixing with alcohol
• Health Canada: No immediate safety concerns related to caffeinated energy drinks, but more research is needed
• Higher risk from energy drinks in CVD, Renal, Liver Disease, Seizure d/o, Diabetes, Mood d/o, Hyperthyroidism

Position Statement: Using Probiotics in the Paediatric Population

• Probiotics: live micro-organisms which confer health effect on host
• Prebiotics: non-viable food components which confer health effect on host by affecting existing microorganisms
• Proven benefits: • Preventing antibiotic-associated diarrhea (2018 data disproves) • Preventing recurrence of C.difficile • Reducing duration of acute infectious diarrhea • Preventing infectious diarrhea • Decreasing colic symptoms • Improving IBS • Preventing NEC >1000g babies
• Small risk in immunocompromised patients

Position Statement: The Baby-Friendly Initiative

• Benefits of breastfeeding: • Decreases infections in infancy • Reduced SIDS • Enhanced neurocognitive testing • Decreased maternal breast and ovarian cancer • Economical
• Requirements for “Baby-Friendly Initiative Integrated 10 Steps for Hospitals and Community Health Services”
• Breastfeeding should be the gold standard
• Pasteurized donor milk recommended if no BM available
• Delay introduction of pacifiers until BF established
• Contraindications: HIV+, cytotoxic or radioactive treatment in mother, galactosemia

Position Statement: Human Milk Banking

• Donor milk prioritized for hospitalized newborns
• Statistics in this position statement are outdated (2010); cross-reference against other data
• Description of testing, collection, and processing techniques
• Pasteurization inactivates pathogens and partially reduces beneficial immune cells
• Canadian Pediatric Society does not endorse unprocessed human milk

Pediatric Gastroenterology and Hepatology

• The course is led by Dr. Nikhil Pai, Associate Professor, Pediatric GI & Nutrition, McMaster University.

Objectives

• Review RCPSC Training Objectives for Pediatric Gastroenterology.
• Review current evidence-based guidelines for managing RCPSC recognized problems.
• Prepare for clinical scenarios that may be encountered on MCQ/OSCE.

Outline of Topics

• 14 topics covered, including:
  • Malabsorption
  • Celiac Disease
  • IBD
  • Constipation
  • Diarrhea
  • GERD & Dysphagia
  • Cow's Milk Protein Allergy
  • Intestinal Bleeding
  • GI Infections
  • Functional GI Disorders
  • Liver Dysfunction & Failure
  • Infectious Hepatitis
  • Liver Transplantation

Malabsorption

• Failure to thrive and chronic diarrhea are common OSCE/MCQ scenarios.
• Approach to malabsorption:
  • Decreased intake
  • Malabsorption
  • Hypermetabolism
• Malabsorption categorized by major macronutrients:
  • Fat malabsorption: Biliary, Pancreas, Ileum
  • Protein malabsorption: Pancreas, SI
  • Carbohydrate malabsorption: Primary causes (enzyme deficiencies), Dietary causes (saturated normal enzyme levels)
• Panmalabsorption: Generalized intestinal inflammation/resection

Celiac Disease

• Not associated with an increased risk: William's Syndrome
• Associated with an increased risk:
  • Type 1 Diabetes
  • IgA Deficiency
  • Down Syndrome
  • Turner Syndrome
  • First Degree Relative with Celiac
• Diagnosis: Bloodwork +ve (not sufficient alone), Intestinal Biopsy (Duodenum/Jejunum)
• Treatment: Lifelong gluten-free diet
• Typical Celiac Disease: Autoimmune enteropathy caused by systemically acting antibodies against gluten
• Extraintestinal manifestations:
  • Dermatitis Herpetiformis
  • Osteopenia/Osteoporosis
  • Short Stature
  • Delayed Puberty
  • Iron Deficiency Anemia
  • Hepatitis
  • Arthritis
  • Epilepsy with Occipital Lobe Calcifications

Inflammatory Bowel Disease (IBD)

• Not a unique sign of Crohn's Disease: Hypoalbuminemia
• Inflammatory Bowel Disease:
  • Ulcerative Colitis
  • Crohn's Disease
• Ulcerative Colitis vs Crohn's:
  • Macroscopic: Rectum, Distribution, Terminal Ileum, Serosa, Bowel Wall, Mucosa, Stricture, Fistula, Erythema Nodosum, Uveitis, PSC
  • Microscopic: Inflammation, Lymphoid Hyperplasia, Crypt Abscess, Mucus Depletion, Granuloma, Submucosal Fibrosis
• Major IBD Medication Classes:
  • Induce Remission: Tube feeds, Corticosteroids, 5-ASA, Biologics
  • Maintain Remission: 5-ASA, Tube feeds, Azathioprine, Methotrexate, Biologics

Constipation

• Not an organic cause of constipation: Hyperkalemia
• Chronic Constipation:
  • Functional (>90%): Patient eventually develops megarectum, *Encopresis (“diarrhea”) due to overflow
  • Organic (10%): Not necessary to investigate on first visit, screen if patient fails first-line treatment
• Laxatives by Category:
  • Osmotic: Lactulose, PEG3350, Magnesium Citrate
  • Stimulant: Picosalax, Glycerine suppository, Bisacodyl, Senokot
  • Lubricant: Mineral Oil
  • Prokinetic: Prucalopride, Linaclotide

Functional Gastrointestinal Disorders (FGIDs)

• Childhood/Adolescence FGIDs:

  • Nausea and vomiting disorders
  • Abdominal Migraine
  • Functional abdominal pain
  • Defecation disorders
  • Functional constipation
  • Nonretentive fecal incontinence### Functional Gastrointestinal Disorders in Infants and Toddlers

• Rumination syndrome: repeated painless regurgitation and rechewing or expulsion of food that begins soon after ingestion of a meal, does not occur during sleep, no retching, no organic explanation, and responds to relaxation therapies and avoidance of behavioral reinforcement.

• Rumination syndrome is treated with frequent holding and social interaction.

Nausea & Vomiting Disorders

• Rumination syndrome: begins soon after ingestion of a meal, does not occur during sleep, no retching, no organic explanation, and responds to relaxation therapies and avoidance of behavioral reinforcement.
• Cyclic vomiting syndrome: ≥2 episodes of intense nausea and hyperemesis or retching lasting hours to days, episodes are stereotypical, return to usual state of health lasting weeks to months, symptoms not attributable to other conditions, and family history of migraine.

Abdominal Pain Disorders

• Irritable bowel syndrome: abdominal pain >4 times/month with ≥1 of the following symptoms: timing related to defecation, change in frequency of stool, and change in form of stool; if patient experiences constipation (IBS-C), pain does not resolve with resolution of constipation.
• Functional abdominal pain: very common, occurs at least 4 times per month, includes episodic or continuous abdominal pain, and insufficient criteria for other FGID's.

Hepatology

• Hepatomegaly approach: 1) hepatitis (inflammation), 2) storage disorders (glycogen, lipid, protein, iron), 3) infiltrative (benign liver tumors, malignant liver tumors, disseminated tumors), 4) biliary obstruction, and 5) posthepatic obstruction (cardiac, thrombus, intrahepatic).
• Gilbert's syndrome: autosomal dominant, genetic defect in glucuronyl transferase UDP1A1 promoter region, fasting bilirubin >40, and 10yo Wilson's (90%).
• Causes of acute liver failure by age group: autoimmune, viral hepatitis, shock/ischemia, and others.

Infectious Hepatitis

• Chronic hepatitis B: HBsAg+ for >6 months, ALT >2x normal, and evidence of viral replication; treat with IFN-α or lamivudine, 20-58% spontaneous conversion/clearance.
• Surveillance recommendations: measure ALT q6months in children >2yo, measure HBeAg and HBeAb yearly in patients with normal ALT, liver biopsy in children >2yo with elevated ALT, examine for chronic liver disease, immunize household and patient against Hepatitis A, alpha fetoprotein and ultrasound annually.

Liver Transplantation Long-term Follow-up

• Prognosis: spontaneous seroconversion and clearance may be as high as 70-80%, risk of hepatocellular carcinoma (HCC) is 15-35X higher, lifetime risk of HCC or cirrhosis is 15-25%.
• Surveillance recommendations: measure ALT q6months in children >2yo, measure HBeAg and HBeAb yearly in patients with normal ALT, liver biopsy in children >2yo with elevated ALT, examine for chronic liver disease, immunize household and patient against Hepatitis A, alpha fetoprotein and ultrasound annually.

Miscellaneous Hepatology Topics

• Non-alcoholic fatty liver disease (NAFLD): umbrella term, NAFLD: simple steatosis vs. NASH, consider when BMI >85%, diagnosis of exclusion, only effective treatments: weight loss, exercise.
• Chronic hepatitis in pediatrics: differential diagnosis, consider... Doppler U/S, adolescent history, autoimmune hepatitis, A1AT deficiency, Wilson's disease, celiac disease, infectious hepatitis.

Pancreatitis

• Acute management: fluids (1.5-2x maintenance), enteral nutrition early (PO/GT à NJ à TPN), watch for complications (SIRS response).

Delayed Gastric Emptying

• Descriptive term with several causes, idiopathic, postinfectious, inflammatory/autoimmune, neurologic, medication/toxins, and postsurgical.### Rome IV Criteria for Functional Gastrointestinal Disorders in Infants and Toddlers
• Defecatory Disorders:
  • Functional Constipation: occurs ≥1/week for ≥2 months, not IBS, ≥2 symptoms in a child developmentally ≥4yo
    • £2 bowel movements/week
    • ≥1 episode of fecal incontinence/week
    • Retentive posturing
    • Painful or hard bowel movements
    • Large fecal mass in rectum
    • Large diameter stools that may block toilet
  • Nonretentive Fecal Incontinence: ≥1/month defecation in places inappropriate to social context, no fecal retention, not attributable to another condition

Complications of Acute Liver Failure

• Encephalopathy
• Cerebral edema
• Pulmonary effects
• Coagulopathy and hemorrhage
• Bone marrow failure
• Hypoglycemia
• Electrolyte/Acid-base imbalance
• Renal Dysfunction
• Pancreatitis
• Ascites

Hepatitis B Treatments

• Interferon-a (IFN-a): cytokine, side effects: neutropenia (39%), fever, myalgia, headaches, arthralgia, anorexia, severe mood changes with weight loss
• Nucleoside analogue (e.g., lamivudine): generally well-tolerated, but high mutation rate leading to resistance

Hepatitis C

• RNA virus
• 0.2% of children 6-11yo and 0.4% of children 12-19yo
• Spontaneous clearance in children: 20% in first 3 years of life, up to 50% by age 18
• Cirrhosis takes 10-20 years to develop, if ever
• 6 genotypes, 1-3 most common in North America, genotype 1 carries worst prognosis

Diagnosis of Hepatitis C

• Hepatitis C Ab (high false +ve)
• Confirm with Hepatitis C PCR and genotype
• In at-risk infants, continue screening until at least 18 months of age with two –ve Ab’s tests in a row

Cholelithiasis

• Cholesterol stones
• Brown Pigment stones
• Black Pigment stones (20%): Hematologic origin, think coffee ground emesis

Liver Pearls

• Liver Pearl #1: If AST > ALT, think EtOH, myopathies, renal syndromes, hemolysis (e.g., capillary blood sample), intestinal inflammation, adenovirus infection
• Liver Pearl #2: If ALP is abnormally low, think zinc deficiency; if ALP low or normal + other enzymes high, think Wilson's Disease
• Liver Pearl #3: Vitamin K dependent Factors are: Factor X, Factor IX, Factor VII, Factor II, Protein C, Protein S
• Liver Pearl #4: Factor VIII is the only coagulation factor not made in the liver, distinguishing liver disease from DIC