Pediatric Gastroenterology

Gastrointestinal Conditions

• Diarrhea:
  • Definition: three or more loose stools per day in children, and twice the usual number of stools per day in infants
  • Types: acute (lasting fewer than 7 days and no longer than 14 days), chronic (lasting more than 4 weeks)
  • Causes: GI tract infection, can lead to dehydration and malnutrition
  • Prevention: access to safe drinking water and sanitation
  • Treatment: hydration with hypotonic fluids, resumption of diet, nutrition/hydration support in severe cases
• Constipation:
  • Definition: difficulty emptying bowels, often with hard stool
  • Common pediatric problem, often accompanied by irritability, abdominal pain, and decreased appetite
  • Evaluation: diet for adequate fiber and fluids, consistent meal pattern, daily physical activity
  • Treatment: laxatives and stool softeners as necessary
• Reflux:
  • Definition: gastroesophageal reflux (GER), passage of stomach contents into esophagus
  • Normal physiological process, but can be accompanied by regurgitation, spitting up, or vomiting
  • Diagnosis: identification of symptoms, weight loss, and poor weight gain
  • Treatment: nutrition and feeding modifications, positional modifications, and medications
  • Goal: decrease symptoms while promoting expected growth and development

Food Allergies and Sensitivities

• Food allergy:
  • Definition: adverse reaction to a food or ingredient involving the body's immune system
  • Symptoms: nausea, stomach pain, diarrhea, vomiting
  • Common allergens: cow's milk, egg, peanut, tree nut, soy, wheat, fish, and shellfish
  • Diagnosis: skin prick test, radioallergosorbent test (RAST), and oral food challenge
  • Treatment: removal of offending food, education, and nutrition management
• Food intolerance:
  • Definition: abnormal physical response to food or additive
  • Examples: lactose and gluten intolerances
• Food sensitivity:
  • Definition: difficulty digesting a particular food
  • Onset of symptoms: slower and may last longer

Malnutrition

• Definition: inadequate nutrition leading to impaired growth, development, and function
• Prevalence: common in developing countries, varying based on underlying condition
• Etiology: multiple factors, including poor nutrition, disease, and chronic conditions
• Assessment: anthropometric parameters, growth, chronicity, etiology, and developmental/functional status
• Prevention: screening, nutrition education, and early intervention
• Treatment: addressing specific causes, nutrition-focused physical exam, and nutrition education

Failure to Thrive

• Definition: complex clinical syndrome describing infants and children who require nutrition intervention due to unexplained deficits in growth
• Growth faltering: weight crossing 3 percentiles on standard growth charts over 3 months in infancy and 6 months in the second and third years of life
• Etiology: multiple factors, including inadequate nutrition, feeding difficulties, and psychiatric disorders
• Assessment: interdisciplinary approach, growth history, and feeding and nutrition assessment
• Treatment: targeting suspected causes, addressing feeding difficulties, and providing nutrition therapy

Cancer

• Etiology: interaction of multiple factors, including genetic composition, hormonal reactions, immune deficiencies, diet, and viral infections
• Nutrition assessment: nutrition history, physical assessment, biochemical assessment, and calculations of energy and protein needs
• Nutrition management: maximizing healthy food options, minimizing GI exposure to pathogens, and considering vitamins and minerals
• Considerations: immunosuppressed or low-microbial diet, vitamin and mineral supplementation, and avoiding iron-containing vitamins

Iron Deficiency

• Definition: most common single-nutrient deficiency among children in the developing world
• Prevalence: 6.6% to 15.2% of toddlers, increasing to 40% without dietary fortification
• Risk factors: developing countries, insufficient dietary intake, and intestinal blood loss
• Symptoms: fatigue, weakness, irritability, pallor, and dizziness
• Diagnosis: series of specific blood tests, including hemoglobin concentration measurement
• Prevention: breastfeeding, iron supplementation, and introduction of iron-containing solid foods
• Treatment: supplementation with 3 to 6 mg/kg of body weight for at least 3 months### Newborn Screening and Genetics
• Amino acid metabolism disorders:
  • Inability to correctly metabolize specific amino acids
  • Results in accumulation of neurologically toxic amino acids
  • Examples: Phenylketonuria (PKU), maple syrup urine disease (MSUD), and tyrosinemia type 1 (TYR1)
  • Require metabolic formulas that restrict/limit offending amino acids
• Organic acid metabolism disorders:
  • Characterized by errors in metabolism of branched chain amino acids
  • Result in accumulation of non-amino organic acids and buildup of toxic intermediates
  • Can cause metabolic crises and increases in blood acids and ammonia
  • Examples: Isovaleric acidemia (IVA), Glutaric acidemia type 1 (GA1), Methylmalonic acidemia (MMA), Propionic acidemia (PA)
• Fatty acid oxidation disorders:
  • Characterized by inability to use stored fat for energy
  • Can lead to dangerously low blood glucose levels during times of increased energy needs
  • Examples: Medium-chain acyl-CoA dehydrogenase deficiency (MCAD), Long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency (LCHAD), Very long chain acyl-CoA dehydrogenase deficiency (VLCAD)
• Carbohydrate metabolism disorders:
  • Characterized by errors in metabolism of certain carbohydrates
  • Example: galactosemia, a disorder of galactose metabolism treated with a galactose-restricted diet
• Other disorders screened for:
  • Endocrine disorders: Congenital adrenal hyperplasia, Congenital hypothyroidism
  • Hemoglobinopathies
  • Cystic fibrosis (CF)

Cystic Fibrosis

• Autosomal recessive genetic disorder
• Result of a defective cystic fibrosis transmembrane conductance regulator (CFTR) protein
• Characterized by:
  • Sticky and thick secretions that affect the GI tract, lungs, pancreas, liver, sinuses, and reproductive system
  • Poor weight gain and growth
  • Nutritional management includes:
    • Nutritional assessment
    • Increasing caloric, protein, and fat intake
    • Management of pancreatic insufficiency and pancreatic enzyme replacement
    • Fat-soluble vitamin replacement
    • Monitoring for evidence of vitamin deficiency

Down Syndrome

• Characterized by an extra chromosome 21
• Risk impacted by maternal age
• Can be detected through prenatal screening or blood test after birth
• Affects one in every 700 newborns
• Characterized by:
  • Hypotonia
  • Developmental delay
  • Short stature
  • Mild to moderate intellectual disability
• Infants may have feeding issues and increased risk for overweight/obesity

Spina Bifida

• Neural tube defect characterized by abnormal development of spinal canal
• Lesion location determines severity of weakness or paralysis
• Associated with folate status of mother
• Neonates typically have lesions repaired immediately after birth
• Increases energy, protein, and vitamin/mineral requirements to promote optimal wound healing
• Energy needs similar in infancy to those of healthy infants, but decreased by as much as 50% by 1 year of age
• Often have feeding issues and bladder/bowel dysfunction

Cerebral Palsy

• Caused by brain injury or abnormal brain development
• Results in difficulties with motor control and muscle tone
• Can occur during the prenatal, perinatal, or postnatal period
• Increased risk for cognitive impairment, learning difficulties, intellectual disabilities, hearing and vision problems
• Common nutrition-related problems:
  • Dysphagia
  • Difficulty gaining weight
  • GI problems
  • Drug-nutrient interactions
• Oral motor function affected by decreased jaw, tongue, and lip control
• Reduces ability to chew, swallow, and eat
• May increase risk of aspirating food

Cleft Lip and Palate

• Congenital anomalies that result in incomplete closure of the skin, muscle, and bone of the upper lip and gum line (cleft lip) and incomplete closure of the tissues that form the roof of the mouth (cleft palate)
• Etiology can be genetic, environmental, or idiopathic
• Risk factors:
  • Family members with an orofacial cleft
  • Prenatal exposure to teratogens
• Increases risk of:
  • Feeding difficulties with subsequent poor growth
  • Increased energy requirement
  • Eustachian tube dysfunction
  • Dental, orthodontic, and/or speech problems
  • Gastroesophageal reflux
  • Breathing difficulty (Pierre Robin sequence)
  • Endocrine dysfunction (midline clefting)

Autism Spectrum Disorders

• Neurologically based developmental disorder
• Characterized by difficulties in social interactions and communication
• Often coexist with restricted and repetitive behaviors
• Prevalence/etiology:
  • Reportedly 1 in 68 children in the United States
  • Etiology unknown, but strong likelihood of genetic component
• Risk factors:
  • 50% to 90% have feeding problems
  • Avoidant eating behaviors
  • Sensory-based feeding difficulties
  • Behavioral rigidity around food and food routines
  • Food selectivity by type, texture, and/or presentation
  • Greater prevalence of reported GI symptoms