GI DisorderPart 1 of 4 Lawrence M. Formoso, M.D.
Normal Digestive Tract Phenomena • A fetus can swallow AF as early as 12 wk of gestation • nutritive sucking in neonates 1st develops at about 34 wk of gestation • The coordinated oral and pharyngeal movements necessary for swallowing solids develop within the 1st few months of life • By 1 mo of age, infants appear to show preferences for sweet and salty foods
Infants’ 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 process • Infants swallow air during feeding, and burping is encouraged to prevent gaseous distention of the stomach
Regurgitation, 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 larger • Most often, the infant remains happy, although possibly hungry, after an episode of regurgitation • Episodes may occur from less than one to several times per day • resolves 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
The earliest stools after birth consist of meconium, a dark, viscous material that is normally passed within the 1st 48 hr of life • With the onset of feeding, meconium is replaced by green-brown transition stools, often containing curds, and, after 4–5 days, by yellow-brown milk stools • Stool frequency is extremely variable in normal infants and may vary from none to seven per day • Breast-fed infants may have frequent small, loose stools early (transition stools), and then after 2–3 wk, may have very infrequent soft stools.
Toddler's diarrhea • A pattern of intermittent loose stools • occurs commonly between 1 and 3 yr of age • These otherwise healthy growing children often drink excessive carbohydrate-containing beverages • The stools typically occur during the day and not overnight • The volume of fluid intake is often excessive • limiting sugar-containing beverages and increasing fat in the diet often leads to resolution of the pattern of loose stools.
Nondigestive Tract Causes of Gastrointestinal Symptoms in Children • ANOREXIA • Systemic disease (inflammatory, neoplastic) • Cardiorespiratorycompromise • Iatrogenic—drug therapy, unpalatable therapeutic diets • Depression • Anorexia nervosa • VOMITING • Inborn errors of metabolism • Medications (erythromycin, chemotherapy) • Increased intracranial pressure • Brain tumor • Infection (urinary tract) • Labyrinthitis • Adrenal insufficiency • Pregnancy • Psychogenic • Abdominal migraine • Toxins
Nondigestive Tract Causes of Gastrointestinal Symptoms in Children • DIARRHEA • Infection (otitis media, urinary) • Uremia • Medications (antibiotics, cisapride) • Tumors (neuroblastoma) • Pericarditis • CONSTIPATION • Hypothyroidism • Spinabifida • Psychomotor retardation • Dehydration (diabetes insipidus, renal tubular lesions) • Medications (narcotics) • Lead poisoning • Infant botulism • ABDOMINAL PAIN • Pyelonephritis, 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
Nondigestive Tract Causes of Gastrointestinal Symptoms in Children • ABDOMINAL DISTENTION OR MASS • Ascites(nephrotic syndrome, neoplasm, heart failure) • Discrete mass (Wilms tumor, hydronephrosis, neuroblastoma, mesenteric cyst, hepatoblastoma, lymphoma) • Pregnancy • JAUNDICE • Hemolytic disease • Urinary tract infection • Sepsis • Hypothyroidism • Panhypopituitarism
Major Symptoms and Signs of Digestive Tract Disorders • Dysphagia, or difficulty swallowing, may be caused by a structural defect or motility disorder • Structural defects that cause a fixed impediment to the food bolus arise from narrowing within the esophagus • stricture, web, or tumor • Most nonstructural causes of dysphagia are caused by motility abnormalities of the oropharynx or the esophagus • transfer dysphagia - Dysphagiaduring the oropharyngeal phase of swallowing • usually associated with neuromuscular disorders (cerebral palsy) • The sensation that something is stuck in the upper esophagus is globus (formerly termed globushystericus) • associated with GER
Major Symptoms and Signs of Digestive Tract Disorders • NontransferDysphagia • Esophageal 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 infancy • An esophageal foreign body or a stricture secondary to a caustic ingestion also causes dysphagia • REGURGITATION • effortless movement of stomach contents into the esophagus and mouth • infants with regurgitation are often hungry immediately after an episode • Regurgitation is a result of GER through an incompetent or, in infants, immature lower esophageal sphincter • regurgitation or “spitting” resolves with maturity
Differential Diagnosis of Emesis During Childhood • INFANT • Gastroenteritis • Gastroesophageal reflux • Overfeeding • Anatomic obstruction • Systemic infection • Pertussis syndrome • Otitis media • CHILD • Gastroenteritis • Gastritis • Systemic infection • Toxic ingestion • Pertussis syndrome • Medication • (GERD) • Sinusitis • Otitismedia
Differential Diagnosis of Emesis During Childhood • ADOLESCENT • Gastroenteritis • GERD • Toxic ingestion • Systemic infection • Gastritis • Sinusitis • Inflammatory bowel disease • Appendicitis • Migraine • Pregnancy • Medication • Ipecac abuse/bulimia
Major Symptoms and Signs of Digestive Tract Disorders • ANOREXIA • Hunger and satiety centers are located in the hypothalamus • The afferent nerves from the gastrointestinal tract to these brain centers are important determinants of the anorexia that characterizes many diseases of the stomach and intestine • Satiety 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
Major Symptoms and Signs of Digestive Tract Disorders • Vomiting • is a highly coordinated reflex process that may be preceded by increased salivation and begins with involuntary retching • Violent descent of the diaphragm and constriction of the abdominal muscles with relaxation of the gastric cardia actively force gastric contents back up the esophagus • coordinated 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
Cyclic vomiting • is a syndrome with numerous episodes of vomiting interspersed with well intervals • onset is usually between 2 and 5 yr of age • the 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 hour • Patients may have a prodrome of pallor, intolerance of noise or light, nausea, lethargy, and headache or fever • Precipitants include infection, stress, and excitement
Cyclic vomiting • Laboratory 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 ondansetron • Prevention may be possible with the antimigraine agent amitriptyline or cyproheptadine
Pharmacologic Therapies for Vomiting Episodes • Reflux • Dopamine 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) • Chemotherapy • Metoclopramide;(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)
Pharmacologic Therapies for Vomiting Episodes • Motion sickness/vestibular disorder • Antihistamine:dimenhydrinate(Dramamine) (1 mg/kg tid–qid PO) • Anticholinergic:scopolamine(TransdermScōp) (adults: 1 patch/3 days) • Adrenal crisis • Steroids:cortisol(2 mg/kg bolus IV followed by 0.2–0.4 mg/kg/hr IV [± 1 mg/kg IM])
Pharmacologic 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: • Serotoninergic5-HT3 antagonist: • Ondansetron:(0.15–0.3 mg/kg tid IV/PO) • Granisetron(Kytril) (10 μg/kg q4–6h IV) • Nonsteroidalantiinflammatory 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
Causes of Gastrointestinal Obstruction • ESOPHAGUS • Congenital • Esophageal atresia • Vascular rings • Schatzkiring • Tracheobronchialremnant • Acquired • Esophageal stricture • Foreign body • Achalasia • Chagas disease • Collagen vascular disease
Causes of Gastrointestinal Obstruction • STOMACH • Congenital • Antralwebs • Pyloric stenosis • Acquired • Bezoars/foreign body • Pyloric stricture (ulcer) • Chronic granulomatous disease of childhood • Eosinophilic gastroenteritis • Crohn disease • Epidermolysisbullosa
Causes of Gastrointestinal Obstruction • SMALL INTESTINE • Congenital • Duodenal atresia • Annular pancreas • Malrotation/volvulus • Malrotation/Ladd bands • Ilealatresia • Meconiumileus • Meckeldiverticulum with volvulus or intussusception • Inguinal hernia Intestinal duplication • Acquired • Postsurgical adhesions • Crohndisease • Intussusception • Distal ileal obstruction syndrome (cystic fibrosis) • Duodenal hematoma • Superior mesenteric artery syndrome
Causes of Gastrointestinal Obstruction • COLON • Congenital • Meconiumplug • Hirschsprungdisease • Colonic atresia, stenosis • Imperforate anus • Rectal stenosis • Pseudo- obstruction • Volvulus • Colonic duplication • Acquired • Ulcerative colitis (toxic megacolon) • Chagasdisease • Crohndisease • Fibrosingcolonopathy (cystic fibrosis)
Major Symptoms and Signs of Digestive Tract Disorders • DIARRHEA • excessive 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 adult • The greatest volume of intestinal water is absorbed in the small bowel; the colon concentrates intestinal contents against a high osmotic gradient • The basis for all diarrhea is disturbed intestinal solute transport
Mechanisms of Diarrhea • Secretory • Decreased absorption, increased secretion, electrolyte transport • Cholera, toxigenicE. 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 leukocytes • Osmotic • Maldigestion, transport defects ingestion of unabsorbable • Lactase deficiency, glucose-galactosemalabsorption, lactulose, laxative abuse • Stops with fasting; increased breath hydrogen with carbohydrate malabsorption; no stool leukocytes
Mechanisms of Diarrhea • Increased motility • Decreased transit time • Irritable bowel syndrome, thyrotoxicosis, postvagotomy dumping syndrome • Infection may also contribute to increased motility • Decreased motility • Defect in neuromuscular unit(s) • Stasis (bacterial overgrowth) • Mucosal invasion • Inflammation, decreased colonic reabsorption, increased motility • Salmonella, Shigella, infection; amebiasis; Yersinia, Campylobacter infections • Dysentery evident in blood, mucus, and WBCs • Blood and increased WBCs in stool
Differential Diagnosis of Diarrhea • INFANT Common: • Gastroenteritis • Systemic infection • Antibiotic associated • Overfeeding Rare: • Primary disaccharidasedeficiency • Hirschsprung toxic colitis • Adrenogenitalsyndrome • Neonatal opiate withdrawal • CHILD • Gastroenteritis • Food poisoning • Systemic infection • Antibiotic associated • Toxic ingestion • ADOLESCENT • Gastroenteritis • Food poisoning • Antibiotic associated • Hyperthyroidism
Major Symptoms and Signs of Digestive Tract Disorders • CONSTIPATION • is relative and depends on stool consistency, stool frequency, and difficulty in passing the stool • A normal child may have a soft stool only every 2nd or 3rd day without difficulty; this is not constipation • A hard stool passed with difficulty every 3rd day should be treated as constipation • Constipation can arise from defects either in filling or emptying the rectum • A nursing infant may have very infrequent stools of normal consistency; this is usually a normal pattern • True constipation in the neonatal period is most likely secondary to Hirschsprung disease, intestinal pseudo-obstruction, or hypothyroidism.
Major Symptoms and Signs of Digestive Tract Disorders • ABDOMINAL PAIN Visceral pain • tends to be experienced in the dermatome from which the affected organ receives innervation • Painful stimuli originating in the liver, pancreas, biliary tree, stomach, or upper bowel are felt in the epigastrium • pain from the distal small bowel, cecum, appendix, or proximal colon is felt at the umbilicus • pain from the distal large bowel, urinary tract, or pelvic organs is usually suprapubic Parietal 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.
Major Symptoms and Signs of Digestive Tract Disorders • GASTROINTESTINAL HEMORRHAGE • Bleeding can occur anywhere along the gastrointestinal tract, and identification of the site may be challenging • Evaluation of the small intestine is facilitated by capsule camera endoscopy • Erosive damage to the mucosa of the gastrointestinal tract is the most common cause of bleeding, also variceal bleeding secondary to portal hypertension occurs frequently • bleeding originating in the esophagus, stomach, or duodenum, it may cause hematemesis
GASTROINTESTINAL HEMORRHAGE • When exposed to gastric or intestinal juices, blood quickly darkens to resemble coffee grounds; massive bleeding is likely to be red • Red 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
Differential Diagnosis of Gastrointestinal Bleeding in Childhood • INFANT • Common: • Bacterial enteritis • Milk protein allergy • Intussusception • Swallowed maternal blood • Anal fissure • Lymphonodularhyperplasia • Rare: • Volvulus • Necrotizing enterocolitis • Meckeldiverticulum • Stress ulcer, stomach • Coagulation disorder (hemorrhagic disease of newborn)
CHILD • Common: • Bacterial enteritis • Anal fissure • Colonic polyps • Intussusception • Peptic ulcer/gastritis • Swallowed epistaxis • Prolapse(traumatic) gastropathy 2° emesis • Mallory-Weiss syndrome • Rare: • Esophageal varices • Esophagitis • Meckeldiverticulum • Lymphonodularhyperplasia • Henoch-Schönleinpurpura • Foreign body • Hemangioma, arteriovenous malformation • Sexual abuse • Hemolytic-uremic syndrome • Inflammatory bowel disease • Coagulopathy
ADOLESCENT • Common: • Bacterial enteritis • Inflammatory bowel disease • Peptic ulcer/gastritis • Prolapse(traumatic) gastropathy 2° emesis • Mallory-Weiss syndrome • Colonic polyps • Rare: • Hemorrhoids • Esophageal varices • Esophagitis • Telangiectasia-angiodysplasia • Gay bowel disease • Graft versus host disease