2Normal Digestive Tract Phenomena A fetus can swallow AF as early as 12 wk of gestationnutritive sucking in neonates 1st develops at about 34 wk of gestationThe coordinated oral and pharyngeal movements necessary for swallowing solids develop within the 1st few months of lifeBy 1 mo of age, infants appear to show preferences for sweet and salty foods
3Infants’ interest in solids increases at about 4 mo of age The recommendation to begin solids at 6 mo of age is based on nutritional and cultural concepts rather than maturation of the swallowing processInfants swallow air during feeding, and burping is encouraged to prevent gaseous distention of the stomach
4Regurgitation, the result of gastroesophageal reflux, occurs commonly in the 1st year of life volumes of emesis are commonly ≈15–30 mL but may occasionally be largerMost often, the infant remains happy, although possibly hungry, after an episode of regurgitationEpisodes may occur from less than one to several times per dayresolves in 80% of infants by 6 mo of age and in 90% by 12 mo.Complications of gastroesophageal reflux include failure to thrive, pulmonary disease (apnea or aspiration pneumonitis), and esophagitis with its sequelae
5The earliest stools after birth consist of meconium, a dark, viscous material that is normally passed within the 1st 48 hr of lifeWith the onset of feeding, meconium is replaced by green-brown transition stools, often containing curds, and, after 4–5 days, by yellow-brown milk stoolsStool frequency is extremely variable in normal infants and may vary from none to seven per dayBreast-fed infants may have frequent small, loose stools early (transition stools), and then after 2–3 wk, may have very infrequent soft stools.
6Toddler's diarrhea A pattern of intermittent loose stools occurs commonly between 1 and 3 yr of ageThese otherwise healthy growing children often drink excessive carbohydrate-containing beveragesThe stools typically occur during the day and not overnightThe volume of fluid intake is often excessivelimiting sugar-containing beverages and increasing fat in the diet often leads to resolution of the pattern of loose stools.
7Nondigestive Tract Causes of Gastrointestinal Symptoms in Children ANOREXIASystemic disease (inflammatory, neoplastic)Cardiorespiratory compromiseIatrogenic—drug therapy, unpalatable therapeutic dietsDepressionAnorexia nervosaVOMITINGInborn errors of metabolismMedications (erythromycin, chemotherapy)Increased intracranial pressureBrain tumorInfection (urinary tract)LabyrinthitisAdrenal insufficiencyPregnancyPsychogenicAbdominal migraineToxins
8Nondigestive Tract Causes of Gastrointestinal Symptoms in Children DIARRHEAInfection (otitis media, urinary)UremiaMedications (antibiotics, cisapride)Tumors (neuroblastoma)PericarditisCONSTIPATIONHypothyroidismSpina bifidaPsychomotor retardationDehydration (diabetes insipidus, renal tubular lesions)Medications (narcotics)Lead poisoningInfant botulismABDOMINAL PAINPyelonephritis, hydronephrosis, renal colic Pneumonia Pelvic inflammatory disease Porphyria Angioedema Endocarditis Abdominal migraine Familial Mediterranean fever Sexual or physical abuse Systemic lupus erythematosus School phobia Sickle cell crisis Vertebral disk inflammation Medications (NSAIDs) Pelvic osteomyelitis
9Nondigestive Tract Causes of Gastrointestinal Symptoms in Children ABDOMINAL DISTENTION OR MASSAscites (nephrotic syndrome, neoplasm, heart failure)Discrete mass (Wilms tumor, hydronephrosis, neuroblastoma, mesenteric cyst, hepatoblastoma, lymphoma)PregnancyJAUNDICEHemolytic diseaseUrinary tract infectionSepsisHypothyroidismPanhypopituitarism
10Major Symptoms and Signs of Digestive Tract Disorders Dysphagia, or difficulty swallowing, may be caused by a structural defect or motility disorderStructural defects that cause a fixed impediment to the food bolus arise from narrowing within the esophagusstricture, web, or tumorMost nonstructural causes of dysphagia are caused by motility abnormalities of the oropharynx or the esophagustransfer dysphagia- Dysphagia during the oropharyngeal phase of swallowingusually associated with neuromuscular disorders (cerebral palsy)The sensation that something is stuck in the upper esophagus is globus (formerly termed globus hystericus)associated with GER
11Major Symptoms and Signs of Digestive Tract Disorders Nontransfer DysphagiaEsophageal web, tracheobronchial remnant, or vascular ring may cause dysphagia in infancy.A Schatzki ring, a thin ring of tissue near the lower esophageal sphincter, is another mechanical cause of recurrent dysphagia presenting after infancyAn esophageal foreign body or a stricture secondary to a caustic ingestion also causes dysphagiaREGURGITATIONeffortless movement of stomach contents into the esophagus and mouthinfants with regurgitation are often hungry immediately after an episodeRegurgitation is a result of GER through an incompetent or, in infants, immature lower esophageal sphincterregurgitation or “spitting” resolves with maturity
12Differential Diagnosis of Emesis During Childhood GastroenteritisGastritisSystemic infectionToxic ingestionPertussis syndromeMedication(GERD)SinusitisOtitis mediaINFANTGastroenteritisGastroesophageal refluxOverfeedingAnatomic obstructionSystemic infectionPertussis syndromeOtitis media
13Differential Diagnosis of Emesis During Childhood ADOLESCENTGastroenteritisGERDToxic ingestionSystemic infectionGastritisSinusitisInflammatory bowel diseaseAppendicitisMigrainePregnancyMedicationIpecac abuse/bulimia
14Major Symptoms and Signs of Digestive Tract Disorders ANOREXIAHunger and satiety centers are located in the hypothalamusThe afferent nerves from the gastrointestinal tract to these brain centers are important determinants of the anorexia that characterizes many diseases of the stomach and intestineSatiety is stimulated by distention of the stomach or upper small bowel, the signal being transmitted by sensory afferents, which are especially dense in the upper gut
15Major Symptoms and Signs of Digestive Tract Disorders Vomitingis a highly coordinated reflex process that may be preceded by increased salivation and begins with involuntary retchingViolent descent of the diaphragm and constriction of the abdominal muscles with relaxation of the gastric cardia actively force gastric contents back up the esophaguscoordinated in the medullary vomiting center, which is influenced directly by afferent innervation and indirectly by the chemoreceptor trigger zone and higher central nervous system (CNS) centers
16Cyclic vomitingis a syndrome with numerous episodes of vomiting interspersed with well intervalsonset is usually between 2 and 5 yr of agethe frequency of vomiting episodes is variable (average of 12 episodes per yr)with each episode typically lasting 2–3 days, with four or more emesis episodes per hourPatients may have a prodrome of pallor, intolerance of noise or light, nausea, lethargy, and headache or feverPrecipitants include infection, stress, and excitement
17Cyclic vomitingLaboratory evaluation is based on a careful history and physical examination and may include, if indicated, endoscopy, contrast gastrointestinal radiography, brain MRI, and metabolic studies (lactate, organic acids, ammonia)Treatment includes hydration and ondansetronPrevention may be possible with the antimigraine agent amitriptyline or cyproheptadine
18Pharmacologic Therapies for Vomiting Episodes RefluxDopamine antagonist: metoclopramide (Reglan) (0.1–0.2 mg/kg qid PO/IV)Peripheral dopamine antagonist: domperidone (Motilium) (0.2–0.6 mg/kg tid–qid PO)ChemotherapyMetoclopramide; (0.5–1.0 mg/kg qid IV, with antihistamine prophylaxis of extrapyramidal side effects)Serotoninergic 5-HT3 antagonist: ondansetron (Zofran) (0.15–0.3 mg/kg tid IV/PO)Phenothiazines:(extrapyramidal, hematologic side effects)Prochlorperazine (Compazine) (≈0.3 mg/kg bid–tid PO)Chlorpromazine (Thorazine) (>6 mo of age: 0.5 mg/kg tid–qid PO/IV)Steroids:dexamethasone (Decadron) (0.1 mg/kg tid PO)Cannabinoids:nabilone (tetrahydrocannabinol) (0.05–0.1 mg/kg bid–tid PO)
19Pharmacologic Therapies for Vomiting Episodes Motion sickness/vestibular disorderAntihistamine:dimenhydrinate (Dramamine) (1 mg/kg tid–qid PO)Anticholinergic:scopolamine (Transderm Scōp) (adults: 1 patch/3 days)Adrenal crisisSteroids:cortisol (2 mg/kg bolus IV followed by 0.2–0.4 mg/kg/hr IV [± 1 mg/kg IM])
20Pharmacologic Therapies for Vomiting Episodes Cyclic vomiting syndrome (CVS)Supportive:Analgesic:meperidine (Demerol) (1–2 mg/kg q4–6h IV/IM) Anxiolytic, sedative: Lorazepam (Ativan) (0.05–0.1 mg/kg q6h IV)Antihistamine, sedative: diphenhydramine (Benadryl) (1.25 mg/kg q6h IV)Abortive:Serotoninergic 5-HT3 antagonist:Ondansetron:(0.15–0.3 mg/kg tid IV/PO)Granisetron (Kytril) (10 μg/kg q4–6h IV)Nonsteroidal antiinflammatory agent (GI ulceration side effect):Ketorolac (Toradol) (0.5–1.0 mg/kg q6–8h IV)Serotoninergic 5-HT1D agonist: sumatriptan (Imitres) (>40 kg; 20 mg intranasally/25 mg PO, one time only)Prophylactic:(if >1 CVS bout/month;taken daily)Antimigraine, β-adrenergic blocker: propranolol (Inderal) (0.5–2.0 mg/kg bid PO)Antimigraine, antihistamine: cyproheptadine (Periactin) (0.25–0.5 mg/kg/day ÷ bid–tid PO)Antimigraine, tricyclic antidepressant: amitriptyline (Elavil) (0.33–0.5 mg/kg tid PO, and titrate to maximum of 3.0 mg/kg/day as needed; obtain baseline ECG at start of therapy, and consider monitoring drug levels)Antimigraine antiepileptic: Phenobarbital (Luminal) (2–3 mg/kg qhs)Erythromycin:Low estrogen oral contraceptives: consider for catamenial CVS episodes
21Causes of Gastrointestinal Obstruction ESOPHAGUSCongenitalEsophageal atresia Vascular rings Schatzki ring Tracheobronchial remnantAcquiredEsophageal stricture Foreign body Achalasia Chagas disease Collagen vascular disease
22Causes of Gastrointestinal Obstruction STOMACHCongenitalAntral webs Pyloric stenosisAcquiredBezoars/foreign body Pyloric stricture (ulcer) Chronic granulomatous disease of childhood Eosinophilic gastroenteritis Crohn disease Epidermolysis bullosa
23Causes of Gastrointestinal Obstruction SMALL INTESTINECongenitalDuodenal atresia Annular pancreas Malrotation/volvulus Malrotation/Ladd bands Ileal atresia Meconium ileus Meckel diverticulum with volvulus or intussusception Inguinal hernia Intestinal duplicationAcquiredPostsurgical adhesions Crohn disease Intussusception Distal ileal obstruction syndrome (cystic fibrosis) Duodenal hematoma Superior mesenteric artery syndrome
25Major Symptoms and Signs of Digestive Tract Disorders DIARRHEAexcessive loss of fluid and electrolyte in the stool.Normally, a young infant has ≈5 g/kg of stool output per day; the volume increases to 200 g/24 hr in an adultThe greatest volume of intestinal water is absorbed in the small bowel; the colon concentrates intestinal contents against a high osmotic gradientThe basis for all diarrhea is disturbed intestinal solute transport
26 Mechanisms of Diarrhea SecretoryDecreased absorption, increased secretion, electrolyte transportCholera, toxigenic E. coli; carcinoid, VIP, neuroblastoma, congenital chloride diarrhea, Clostridium difficile, cryptosporidiosis (AIDS)Persists during fasting; bile salt malabsorption may also increase intestinal water secretion; no stool leukocytesOsmoticMaldigestion, transport defects ingestion of unabsorbableLactase deficiency, glucose-galactose malabsorption, lactulose, laxative abuseStops with fasting; increased breath hydrogen with carbohydrate malabsorption; no stool leukocytesPrimary mechanism, Defect, Examples
27 Mechanisms of Diarrhea Increased motilityDecreased transit timeIrritable bowel syndrome, thyrotoxicosis, postvagotomy dumping syndromeInfection may also contribute to increased motilityDecreased motilityDefect in neuromuscular unit(s)Stasis (bacterial overgrowth)Mucosal invasionInflammation, decreased colonic reabsorption, increased motilitySalmonella, Shigella, infection; amebiasis; Yersinia, Campylobacter infectionsDysentery evident in blood, mucus, and WBCsBlood and increased WBCs in stool
29Major Symptoms and Signs of Digestive Tract Disorders CONSTIPATIONis relative and depends on stool consistency, stool frequency, and difficulty in passing the stoolA normal child may have a soft stool only every 2nd or 3rd day without difficulty; this is not constipationA hard stool passed with difficulty every 3rd day should be treated as constipationConstipation can arise from defects either in filling or emptying the rectumA nursing infant may have very infrequent stools of normal consistency; this is usually a normal patternTrue constipation in the neonatal period is most likely secondary to Hirschsprung disease, intestinal pseudo-obstruction, or hypothyroidism.
30Major Symptoms and Signs of Digestive Tract Disorders ABDOMINAL PAINVisceral paintends to be experienced in the dermatome from which the affected organ receives innervationPainful stimuli originating in the liver, pancreas, biliary tree, stomach, or upper bowel are felt in the epigastriumpain from the distal small bowel, cecum, appendix, or proximal colon is felt at the umbilicuspain from the distal large bowel, urinary tract, or pelvic organs is usually suprapubicParietal pain impulses travel in C fibers of nerves corresponding to dermatomes T6–L1; such pain tends to be more localized and intense than visceral pain.
31Major Symptoms and Signs of Digestive Tract Disorders GASTROINTESTINAL HEMORRHAGEBleeding can occur anywhere along the gastrointestinal tract, and identification of the site may be challengingEvaluation of the small intestine is facilitated by capsule camera endoscopyErosive damage to the mucosa of the gastrointestinal tract is the most common cause of bleeding, also variceal bleeding secondary to portal hypertension occurs frequentlybleeding originating in the esophagus, stomach, or duodenum, it may cause hematemesis
32GASTROINTESTINAL HEMORRHAGE When exposed to gastric or intestinal juices, blood quickly darkens to resemble coffee grounds; massive bleeding is likely to be redRed or maroon blood in stools, hematochezia, signifies either a distal bleeding site or massive hemorrhage above the distal ileum.Moderate to mild bleeding from sites above the distal ileum tends to cause blackened stools of tarry consistency (melena); major hemorrhages in the duodenum or above can also cause melena
33Differential Diagnosis of Gastrointestinal Bleeding in Childhood INFANTCommon:Bacterial enteritisMilk protein allergyIntussusceptionSwallowed maternal bloodAnal fissureLymphonodular hyperplasiaRare:VolvulusNecrotizing enterocolitisMeckel diverticulumStress ulcer, stomachCoagulation disorder (hemorrhagic disease of newborn)