Part 13. The Digestive System

Question 1

Nutritive sucking in neonates first develops at about _ wk of gestation.

Answer 1

34

Question 2

Regurgitation gradually resolves in 80% of infants by _ mo of age and in 90% by _ mo.

Answer 2

6
12

Question 3

What is toddler’s diarrhea? What is its cause? How do you manage it?

Answer 3

A pattern of intermittent loose stools, known as toddler’s diarrhea, 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 and unabsorbable carbohydrate-containing beverages and increasing fat in the diet often lead to resolution of the pattern of loose stools.

Question 4

In neonates, The direct bilirubin fraction should account for no more than ____ of the total serum bilirubin.

Answer 4

15–20%

Question 5

____ hyperbilirubinemia, which occurs commonly in normal newborns, tends to tint the sclerae and skin golden yellow, whereas ____ hyperbilirubinemia produces a greenish yellow hue.

Answer 5

Indirect; direct

Question 6

This occurs when the transfer of the food bolus from the mouth to the esophagus is impaired.

Answer 6

Oropharyngeal dysphagia (also termed transfer dysphagia)

Question 7

Acute diarrhea is defined as sudden onset of excessively loose stools of >____ in infants and > ____ in older children which lasts < 14 days.

Answer 7

10 mL/kg/day
200 g/24 hr

Question 8

Describe secretory diarrhea (Presentation / characteristics, pathophysiology)

Answer 8

Secretory diarrhea occurs when the intestinal epithelial cell solute transport system is in an active state of secretion. It is often caused by a secretagogue, such as cholera toxin, binding to a receptor on the surface epithelium of the bowel and thereby stimulating intracellular accumulation of cyclic adenosine monophosphate or cyclic guanosine monophosphate.
It is usually of large volume and persists even with fasting. The stool ion gap is 100 mOsm/kg or less.

Question 9

How to you compute for stool ion gap?

Answer 9

Ion gap = Stool osmalality −[(Stool Na + stool K) × 2]

Question 10

Describe osmotic diarrhea (Presentation / characteristics, pathophysiology)

Answer 10

Osmotic diarrhea occurs after ingestion of a poorly absorbed solute. The solute may be one that is normally not well absorbed (magnesium, phosphate, lactulose, or sorbitol) or one that is not well absorbed because of a disorder of the small bowel (lactose with lactase deficiency or glucose with rotavirus diarrhea).
This form of diarrhea is usually of lesser volume than a secretory diarrhea and stops with fasting. The osmolality of the stool will not be explained by the electrolyte content, because another osmotic component is present and so the anion gap is >100 mOsm.

Question 11

Visceral pain tends to be dull and aching and is experienced in the dermatome from which the affected organ receives innervations.
Painful stimuli originating in the liver, pancreas, biliary tree, stomach, or upper bowel are felt in the ____ ; pain from the distal small bowel, cecum, appendix, or proximal colon is felt at the ____ ; and pain from the distal large bowel, urinary tract, or pelvic organs is usually ____ .

Answer 11

epigastrium
umbilicus
suprapubic

Question 12

When does all 20 primary teeth erupt by?

Answer 12

3 years old

Question 13

When do the permanent teeth start erupting? When is it usually completed?

Answer 13

6 yrs old
13 yrs old

Question 14

Excessive consumption of this during enamel formation affects ameloblastic function, resulting in inconspicuous white, lacy patches on the enamel to severe brownish discoloration and hypoplasia.

Answer 14

Fluoride (Fluorosis - can result from systemic fluoride consumption >0.05 mg/kg/day during enamel formation

Question 15

When is surgical closure of a cleft lip is usually performed?

Answer 15

By 3 mo of age, when the infant has shown satisfactory weight gain and is free of any oral, respiratory, or systemic infection.
The initial repair may be revised at 4 or 5 yr of age. Corrective surgery on the nose may be delayed until adolescence. Nasal surgery can also be performed at the time of the lip repair.

Question 16

In an otherwise healthy child with cleft palate, when is closure of the palate is usually done?

Answer 16

Before 1 yr of age to enhance normal speech development

Question 17

Frequent sequelae of cleft palate

2

Answer 17

Recurrent otitis media
hearing loss

Question 18

Dental defect associated with osteogenesis imperfecta.

Answer 18

Dentinogenesis imperfecta or
hereditary opalescent dentin, is a condition analogous to amelogenesis imperfecta in which the odontoblasts fail to differentiate normally, resulting in poorly calcified dentin

Question 19

This an autosomal dominant condition that includes other findings such as prominent joints, arthritis, hypotonia, hypermobile joints, mitral valve prolapse, hearing loss, spine problems (scoliosis, kyphosis, platyspondyly), and ocular problems (high myopia, glaucoma, cataracts, retinal detachment).

Answer 19

Stickler syndrome (30-50% of pts with Pierre-Robin syndrome also has this)

Question 20

This an autosomal dominant syndrome that primarily affects the face. The facial appearance varies but is characterized by downward-sloping palpebral fissures, colobomas of the lower eyelids, sunken cheekbones, blind fistulas opening between the angles of the mouth and the ears, deformed pinnae, atypical hair growth extend- ing toward the cheeks, receding chin, and large mouth

Answer 20

Mandibulofacial dysostosis (Treacher Collins syndrome or France- schetti syndrome)

Question 21

This group of microorganisms is associated with the development of dental caries. These bacteria have the ability to adhere to enamel, produce abundant acid, and survive at low pH.

Answer 21

Mutans streptococci

Question 22

What is the most cariogenic sugar?

Answer 22

Sucrose.
Dietary behaviors, such as consuming sweetened beverages in a nursing bottle or frequently consuming sticky candies, increase the cariogenic potential of foods because of the long retention of sugar in the mouth

Question 23

Red Flags Suggestive of a Spreading Dental Infection

Answer 23

• Pyrexia
• Tachycardia or tachypnea
• Trismus; may be relative due to pain or absolute due to a collection within the muscle causing muscle spasm in cases of masticator space involvement
• Raised tongue and floor of mouth, drooling
• Periorbital cellulitis
• Difficulty with speaking, swallowing, and breathing
• Hypotension
• Increased white blood cell count
• Lymphadenopathy
• Dehydration

Question 24

What is the antibiotic of choice for dental infections associated with fever, cellulitis, and facial swelling or if it is difficult to anesthetize the tooth in the presence of inflammation?

Answer 24

Penicillin is the antibiotic of choice, except in patients with a history of allergy to this agent. Clindamycin and erythromycin are suitable alternatives. Oral analgesics, such as ibuprofen, are usually adequate for pain control.

Question 25

The most effective preventive measure against dental caries is?

Answer 25

communal water supplies with optimal fluoride content.

Question 26

# Topical fluoride recommended for prevention of dental caries Amount of fluoridated toothpaste for 3-6 y/o

Answer 26

pea-sized (~0.25g) amount on toothbrush

Question 27

# Topical fluoride recommended for prevention of dental caries Amount of fluoridated toothpaste for less than 3 y/o

Answer 27

less than a smear or grain-sized amount of fluo- ridated toothpaste.

Question 28

What comprise the periodontium? | 4

Answer 28

* gingiva, * alveolar bone, * cementum, and * periodontal ligament

Question 29

Name 2 drugs that can induce gingival hyperplasia

Answer 29

Cyclosporine Phenytoin

Question 30

These are yellow-white granules in clusters or plaque-like areas on the oral mucosa, most commonly on the buccal mucosa or lips.

Answer 30

Fordyce granules. They are aberrant sebaceous glands. The glands are present at birth, but they can undergo hypertrophy and first appear as discrete yellowish papules during the preadolescent period in approximately 50% of children. No treatment is necessary.

Question 31

This is a large, soft, mucus-containing swelling in the floor of the mouth. What is its management?

Answer 31

Ranula. The cyst should be excised, and the severed duct should be exteriorized

Question 32

This is a salivary gland lesion caused by a blockage of a salivary gland duct.

Answer 32

Mucocele. It is most common on the lower lip and has the appearance of a fluid-filled vesicle, or a fluctuant nodule with the overlying mucosa being normal in color. Treatment is surgical excision, with removal of the involved accessory salivary gland.

Question 33

What is a hallmark of lack of normal swallowing or of esophageal or upper gastrointestinal tract obstructionin the fetus?

Answer 33

Polyhydramnios

Question 34

This is a reflex wherein facial stimulation by a puff of air can induce swallowing and esophageal peristalsis in healthy young infants.

Answer 34

Santmyer swallow

Question 35

A neonate presenting with frothing and bubbling at the mouth and nose after birth as well as episodes of coughing, cyanosis, and respiratory distress most likely have?

Answer 35

Esophageal atresia. Feeding exacerbates these symptoms, causes regurgitation, and can precipitate aspiration. Aspiration of gastric contents via a distal fistula causes more damaging pneumonitis than aspiration of pharyngeal secretions from the blind upper pouch.

Question 36

What is the most common type of esophageal atresia? Describe it.

Answer 36

Type C. The upper esophagus ends in a blind pouch and the TEF is connected to the distal esophagus

Question 37

How to differentiate between obstructing from motility disorders of the esophagus? | in terms of symptoms

Answer 37

Obstructing lesions classically produce dysphagia to solids earlier and more noticeably than to liquids and can manifest when the infant liquid diet begins to incorporate solids; this contrasts to dysphagia from dysmotility, in which swallowing of liquids is affected as early as, or earlier than, solids.

Question 38

What are the most common external masses that compress the esophagus and produce obstructive symptoms?

Answer 38

Enlarged mediastinal or subcarinal lymph nodes, caused by infection (tuberculosis, histoplasmosis) or neoplasm (lymphoma)

Question 39

This is characterized by loss of LES relaxation and loss of esophageal peristalsis, both contributing to a functional obstruction of the distal esophagus.

Answer 39

Achalasia. Degenerative, autoimmune (antibodies to Auerbach plexus), and infec- tious (Chagas disease caused by Trypanosoma cruzi) factors are possible causes.

Question 40

What comprises the Allgrove syndrome?

Answer 40

Aka triple A syndrome: Achalasia, alacrima, and adrenal insufficiency

Question 41

What would a Barium fluoroscopy show in pts with Achalasia?

Answer 41

Barium fluoroscopy reveals a smooth tapering of the lower esophagus leading to the closed LES, resembling a bird’s beak.

Question 42

What is the most sensitive diagnostic test for Achalasia?

Answer 42

Manometry

Question 43

Two most effective treatment options for Achalasia.

Answer 43

**Pneumatic dilation** is the initial treatment of choice and does not preclude a future **(Heller) myotomy [laparoscopic or surgical]**. Surgeons often supplement a myotomy with an antireflux procedure to prevent the gastroesophageal reflux disease that otherwise often ensues when the sphincter is rendered less competent.

Question 44

This is the primary mechanism allowing reflux to occur, and is defined as simultaneous relaxation of both LES and the surrounding crura.

Answer 44

Transient LES relaxation (TLESR)

Question 45

When does infant reflux peak?

Answer 45

4 mos

Question 46

Children presenting with food refusal or neck contortions (arching, turning of head) associated to reflux is designated as?

Answer 46

Sandifer Syndrome

Question 47

Detection of ____ in tracheal fluid is a marker of reflux-associated aspiration of gastric contents

Answer 47

pepsin

Question 48

What position worsens infant reflux and should be avoided in infants with GERD?

Answer 48

**Seated.** When the infant is awake and observed, prone position and upright carried position can be used to minimize reflux. Lying in the flat supine position and semi-seated positions (e.g., car seats, infant carriers) in the postprandial period are considered provocative positions for GER and therefore should be avoided. In older children, evidence suggests a benefit to left side position and head elevation during sleep. The head should be elevated by elevating the head of the bed, rather than using excess pillows

Question 49

Long-standing esophagitis predisposes to metaplastic transformation of the normal esophageal squamous epithelium into intestinal columnar epithelium, termed ____ , a precursor of esophageal adenocarcinoma.

Answer 49

**Barrett esophagus,** uncommon in children, warrants periodic surveillance biopsies, aggressive pharmacotherapy, and fundoplication for progressive lesions. Adenocarcinoma is rare in children.

Question 50

# Diagnostic Criteria The diagnosis of Eosinophilic esophagitis (EoE) should be considered in the... | 3

Answer 50

* clinical presentation of esophageal dysfunction, associated with * esophageal epithelial infiltration of at least 15 eosinophils (eos) per high power field (hpf) or ~60 eos per mm2, and * after a careful evaluation of non-EoE disorders.

Question 51

Treatment options for EoE

Answer 51

* **Elimination diets** guided by circumstantial evidence and food allergy test results; “6 food elimination diet” removing the major food allergens (milk, soy, wheat, egg, peanuts and tree nuts, seafood); and elemental diet composed exclusively of an amino acid-based formula. * **Topically acting swallowed corticosteroids** (fluticasone without spacer, viscous budesonide suspension) have been used successfully for those who refuse, fail to adhere, or have a poor response to restricted diets.

Question 52

What is the leading cause of infective esophagitis in immunocompetent and immunocompromised children and presents with concurrent oropha- ryngeal infection in the majority of immunocompromised patients?

Answer 52

Candida

Question 53

The leading causes of pediatric portal hypertension are... | 2

Answer 53

1. biliary atresia, and 2. extrahepatic portal vein obstruction

Question 54

What is the preferred diagnostic test for esophageal varices?

Answer 54

**Upper endoscopy** as it provides definitive diagnosis and delineation of details that aid in predicting the risk for bleeding, as well as enabling therapy for acute bleeding episodes via either sclerotherapy or band ligation.

Question 55

How do you differentiate on radiograph where an ingested coin is lodged? | Esophagus or trachea

Answer 55

The flat surface of a coin in the esophagus is seen on the anteroposterior view and the edge on the lateral view. The reverse is true for coins lodged in the trachea; here, the edge is seen anteroposteriorly and the flat side is seen laterally.

Question 56

Sharp objects in the esophagus, multiple magnets or single magnet with a metallic object, or foreign bodies associated with respira- tory symptoms mandate urgent removal within ____ hr of presentation.

Answer 56

12

Question 57

Button batteries, in particular, must be emergently removed within ____ hr of presentation.

Answer 57

Button batteries, in particular, must be emergently removed within 2 hr of presentation regardless of the timing of patient’s last oral intake because they can induce mucosal injury in as little as 1 hr of contact time and involve all esophageal layers within 4 hr.

Question 58

Asymptomatic blunt objects and coins lodged in the esophagus can be observed for up to ____ hr in anticipation of passage into the stomach.

Answer 58

24

Question 59

Recommended as acute treatment for caustic ingestions.

Answer 59

Dilution by water or milk is recommended as acute treatment, but neutralization, induced emesis, and gastric lavage are contraindicated.

Question 60

Carbohydrates, protein, and fat are normally absorbed by which part of the GI tract?

Answer 60

the upper half of the small intestine

Question 61

Most of the sodium, potassium, chloride, and water are absorbed where?

Answer 61

Small bowel

Question 62

Bile salts and vitamin B12 are selectively absorbed in the?

Answer 62

distal ileum

Question 63

Iron is absorbed in the?

Answer 63

duodenum and proximal jejunum

Question 64

An association with pyloric stenosis has been found with the use of this drug in neonates with highest risk if the medication is given within the first 2 wk of life.

Answer 64

erythromycin

Question 65

What is the most common clinical association of pyloric stenosis?

Answer 65

Hyperbilirubinemia, aka icteropyloric syndrome, more commonly unconjugated.

Question 66

What can be seen on contrast studies of patients with pyloric stenosis? | 3

Answer 66

* an elongated pyloric channel (string sign), * a bulge of the pyloric muscle into the antrum (shoulder sign), and * parallel streaks of barium seen in the narrowed channel, producing a “double tract sign”

Question 67

A previously healthy child started having vomiting associated with upper abdominal pain, and with new onset edema and no other causes of protein losses. What is the most common organism causing this condition?

Answer 67

Cytomegalovirus. Condition is hypertrophic gastropathy. Therapy is supportive. Ganciclovir in CMV-positive gastropathy is indicated only in severe cases. There are no official guidelines as far as the length of treatment. In practice, IV therapy is initiated for the 1st 24-48 hr. Treatment is continued with oral valganciclovir for a total of 3 wk. When H. pylori are detected, appropriate treatment is recommended.

Question 68

The presence of polyhydramnios should prompt aspiration of the infant’s stomach immediately after birth. Aspiration of more than 15-20 mL of fluid, particularly if it is bile stained, is highly indicative of?

Answer 68

proximal intestinal obstruction

Question 69

Duodenal atresia results from?

Answer 69

Failed recanalization of the intestinal lumen during gestation.

Question 70

Hallmark of duodenal obstruction? Plain abdominal radiograph finding?

Answer 70

The hallmark of duodenal obstruction is **bilious vomiting** without abdominal distention, which is usually noted on the first day of life. The diagnosis is suggested by the presence of a **double-bubble sign** on a plain abdominal radiograph. The apperance is caused by a distended and gas-filled stomach and proximal duodenum, which are invariably connected.

Question 71

This occurs primarily in newborn infants with cystic fibrosis, an exocrine gland defect of chloride transport that results in abnormally viscous secretions.

Answer 71

**Meconium ileus.** The proximal bowel is dilated and filled with thick meconium that resembles sticky syrup or glue. Peristalsis fails to propel this viscid material forward, and it becomes impacted in the ileum.

Question 72

Plain radiographic findings in distal intestinal obstruction.

Answer 72

In patients with obstruction caused by jejunoileal atresia or long- segment Hirschsprung disease, plain radiographs typically demonstrate multiple air–fluid levels proximal to the obstruction in the upright or lateral decubitus positions. These levels may be absent in patients with meconium ileus because the viscosity of the secretions in the proximal bowel prevents layering. Instead, a typical hazy or ground-glass appearance may be appreciated in the right lower quadrant. This haziness is caused by small bubbles of gas that become trapped in inspissated meconium in the terminal ileal region.

Question 73

A procedure that is used to diagnose meconium ileus that may also be therapeutic.

Answer 73

**Gastrografin enemas** diagnose the obstruction and wash out the inspissated material. Gastrografin is hypertonic, and care must be taken to avoid dehydration, shock, and bowel perforation. The enema may have to be repeated after 8-12 hr. Resection after reduction is not needed if there have been no ischemic complications.

Question 74

Components of heterotaxy syndrome?

Answer 74

complex of congenital anomalies including congenital heart malformations, malrotation, biliary atresia, and either asplenia or polysplenia

Question 75

This is a life-threatening complication of malrotation which occurs when the small bowel twists around the superior mesenteric artery leading to vascular compromise of the bowel. What is its imaging test of choice?

Answer 75

**Volvulus** Upper gastrointestinal series is the imaging test of choice and the gold standard in the evaluation and diagnosis of malrotation and volvulus. It can also reveal a corkscrew appearance of the small bowel or a duodenal obstruction with a bird’s beak appearance of the duodenum.

Question 76

Most common congenital GI anomaly.

Answer 76

**Meckel diverticulum** Rule of 2s found in approximately 2% of the general population, are usually located 2 feet proximal to the ileocecal valve and are approximately 2 inches in length, can contain 2 types of ectopic tissue (pancreatic or gastric), generally present before the age of 2 yr, and are found twice as commonly in females.

Question 77

This presents painless rectal bleeding and with stool that is typically described as brick colored or currant jelly colored.

Answer 77

Meckel diverticulum. The most sensitive study is a Meckel radionuclide scan, which is performed after intravenous infusion of technetium- 99m pertechnetate. The mucus-secreting cells of the ectopic gastric mucosa take up pertechnetate, permitting visualization of the Meckel diverticulum.

Question 78

This is a multisystem autosomal recessive disease that initially presents with severe gastrointestinal disturbances; the neurologic manifestations usually occur later in the illness and may initially be subtle or asymptomatic.

Answer 78

Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE)

Question 79

This is defined as voluntary or involuntary passage of feces into inappropriate places at least once a mo for 3 consecutive months once a chronologic or developmental age of 4 yr has been reached.

Answer 79

Encopresis

Question 80

This is the most common cause of lower intestinal obstruction in neonates, characterized by the absence of ganglion cells in the submucosal and myenteric plexus.

Answer 80

**Hirschsprung Disease (Congenital aganglionic Megacolon)** It is a neurocristopathy of the enteric nervous system, more common in males.

Question 81

# Hirschsprung Disease Observed histologically is an absence of ____ and hypertrophied nerve bundles with high concentrations of acetylcholinesterase between the muscular layers and in the submucosa.

Answer 81

Meissner’s and Auerbach’s plexuses

Question 82

Gold standard for diagnosing Hirschsprung Disease

Answer 82

**Rectal suction biopsy** It should be obtained no closer than 2cm above the dentate line

Question 83

Definitive treatment for Hirschsprung Disease.

Answer 83

Endorectal pull-through procedures

Question 84

In this condition, ganglion cells are present on rectal suction biopsy, but the anorectal manometry is abnormal, with failure of relaxation of the internal anal sphincter in response to rectal distention.

Answer 84

ultrashort-segment Hirschsprung disease, aka anal achalasia

Question 85

Leading cause of death in patients with Hirschsprung disease?

Answer 85

Enterocolitis

Question 86

It is the most common cause of intestinal obstruction between 5 mo and 3 yr of age and the most common abdominal emergency in children younger than 2 yr of age.

Answer 86

Intussusception

Question 87

Most common form of intussusception

Answer 87

Ileocolic

Question 88

Classic triad of intussusception.

Answer 88

**Pain, a palpable sausage-shaped abdominal mass (most often in the right upper abdomen with its long axis cephalocaudal), and bloody or currant jelly stool.** The combination of paroxysmal pain, vomiting, and a palpable abdominal mass has a positive predictive value of >90%; the presence of rectal bleeding increases this to approximately 100%.

Question 89

What is the major causative agent in traveler's diarrhea?

Answer 89

ETEC

Question 90

# In AGE Dehydration must be evaluated rapidly and corrected in ____ hr according to the degree of dehydration and estimated daily requirements.

Answer 90

4 to 6

Question 91

What are the components of the low-osmolality WHO ORS?

Answer 91

75 mEq of sodium, 64 mEq of chloride, 20 mEq of potassium, and 75 mmol of glucose per liter, with total osmolarity of 245 mOsm/L

Question 92

Drugs of choice for treatment of AGE caused by C. difficile

Answer 92

Oral vancomycin and metronidazole for 7-14 days (first line agents) displayed equivalent efficacy in a prospective randomized trial; however, metronidazole is preferred because of lower cost and decreased potential for inducing vancomycin-resistant enterococci.

Question 93

First line tx for moderate to severe diarrhea caused by Shigella

Answer 93

* Ciprofloxacin 15 mg/kg/day PO bid × 3 days; OR * Ceftriaxone 50-100 mg/kg/day IV or IM, qd × 3 days for severe illness requiring parenteral therapy; OR * Azithromycin 12 mg/kg once on 1st day, then 6 mg/kg once daily on days 2 through 4 (total course: 4 days)

Question 94

# AGE The presence of this organism as a cause of AGE is a contraindication to using antimicrobials?

Answer 94

Shiga-toxin producing Escherichia coli

Question 94

The peak age of onset of symptoms of bezoars is?

Answer 94

2nd decade of life

Question 95

What is the method of choice to establish the diagnosis of peptic ulcer disease?

Answer 95

Esophagogastroduodenoscopy

Question 96

What are reliable noninvasive methods of detecting H. pylori infection in patients who do not require endoscopic evaluation? | 2

Answer 96

C-urea breath tests and stool antigen tests