MCQs In GIT And Liver Diseases

Q1 :

A 3-year-old child presents to your office with chronic recurrent diarrhea of 3 months’ duration. He attends child care during the week. He is one of four children in the family, the oldest of whom is 8 years old. Stool microscopic analysis identifies Giardia lamblia. You treat the boy with metronidazole for 10 days. On a follow-up visit 30 days after initiating treatment, the mother states that the symptoms initially improved, but have recurred. Of the following, the BEST explanation for the persistent symptoms is

A. Clostridium difficile infection

B. metronidazole resis ance

C. persistent giardiasis

D. superimposed milk protein allergy

E. undiagnosed celiac disease

Answer :

C


Based on the documented history of giardiasis and ongoing diarrhea for the patient described in the vignette, the most likely cause of his symptoms is persistent giardiasis, most likely from reinfection from one of his siblings or a family pet.

Many Giardia infections are asymptomatic, and siblings, other children in child care, or family pets frequently can be reservoirs for the organism.

Therefore, a patient treated with a course of metronidazole is susceptible to reinfection if he or she is exposed to asymptomatic carriers.

 Metronidazole resistance is extremely rare in Giardia parasites, and based on the history provided, there is no reason to suspect Clostridium difficile infection, celiac disease, or food allergy at this time.

Giardia  parasite exists in two forms, cysts and trophozoites. Cysts  are extremely hardy and can survive in cold water for weeks to months.

 The cysts also are resistant to chlorination. Once animals (eg, dogs, cats, beavers) or humans ingest contaminated water, the cysts mature into trophozoites in the intestine, where they cause small intestinal inflammation, villous atrophy, and malabsorption.

Asymptomatic carriage is more common than symptomatic disease.

However, in patients who do develop symptoms, the most common features are diarrhea, nausea, distention, cramping, and anorexia. 

Because Giardia is a small bowel pathogen, it does not cause rectal bleeding.

The most important aspect to diagnosing Giardia infection is having a strong clinical suspicion.

 The microscopic examination ("O and P" test) has poorer sensitivity (50%) from a single sample and ideally requires microscopic examination of three separate samples.

In contrast, the Giardia antigen-based tests have a sensitivity of approximately 90% from a single stool sample.

However, the O and P examination can identify other potential pathogens (Blastocystis, ameba) that are not identified with the antigen tests.

 In some cases, endoscopy with biopsy may be useful to exclude Giardia or other pathogens and
to characterize the extent of villous atrophy.

Suspected or established giardiasis can be treated with either metronidazole or nitazoxanide.

If asymptomatic carriers are suspected in the family, it may be prudent to evaluate and treat the entire family.

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Q2

You are evaluating a 12-year-old boy who has ulcerative colitis for fatigue, weight loss, and jaundice. The ulcerative colitis has been in remission while he has been receiving 5-amino salicylate therapy.

Of the following, the MOST likely cause of this child's symptoms is:

A.  cholelithiasis

B.  fatty infiltration of the liver

C.  hepatic abscess

D.  hepatitis B infection

E.  sclerosing cholangitis

Answer :

E

Hepatobiliary involvement is seen in 10% to 15% of children and adolescents who have inflammatory bowel disease and is among the most common extraintestinal manifestation associated with these disorders.

Although the course of the liver disease usually is mild, it is more severe in patients who have ulcerative colitis than Crohn disease. The findings associated with these disorders include fatty infiltration, primary sclerosing cholangitis, pericholangitis, chronic hepatitis, cirrhosis, and acalculous cholecystitis.

            Although biochemical or histologic abnormalities such as fatty infiltration and pericholangitis of the liver are found in approximately 50% of pediatric patients who have ulcerative colitis, only 10% to 14% of these children become symptomatic, with jaundice and pain being uncommon. 

            Primary sclerosing cholangitis develops in 3% of children who have inflammatory bowel disease. Chronic ulcerative colitis more often is associated with sclerosing cholangitis than is Crohn disease. Sclerosing cholangitis is characterized by fibrosis and inflammation of the intrahepatic and extrahepatic bile ducts, leading to bile duct obliteration and hepatic failure.  Presenting symptoms include abdominal pain, fatigue, weight loss, jaundice, and pruritus, as described for the boy in the vignette. Patients who have primary sclerosing cholangitis have elevated serum aminotransferase and gamma glutamyl transferase and direct bilirubin concentrations. Antinuclear and anti-smooth muscle antibodies are present in most patients. 

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Q 3

   The mother of a 10-month-old boy, who has been diagnosed as having mild mental retardation, reports that he frequently regurgitates food that he then chews and reswallows. Prior to the regurgitation, he contracts his abdominal muscles aggressively. This action seems to have a calming effect.

Of the following, the MOST likely cause of this behavior is:

A. achalasia

B. gastric outlet obstruction

C. gastroesophageal reflux

D. rumination syndrome

E. Sandifer syndrome


Answer

D

Rumination is defined as frequent regurgitation of previously ingested food into the mouth that then is rechewed and either swallowed or spit out. It is effortless and is not associated with forceful emesis. Occurring most frequently in mentally retarded children, rumination is believed to be a behavioral mechanism for self-stimulation and pleasurable sensation. Mentally healthy infants who are abused or neglected and preterm neonates who have limited contact with their parents also are at risk for developing rumination syndrome.

            During an episode of rumination, the infant appears satisfied and calm. Typically, rumination begins at 5 months of age, although it may begin at any age, and it is five times more common among males than females. Rumination can be associated with gastroesophageal reflux and bulimia, making the distinctions between these disorders difficult. Although children who have rumination often mouth their fingers and fists to initiate a gag reflex, some children learn to ruminate without obvious stimulation. Motility studies have revealed that rumination is associated with voluntary abdominal wall contraction and pharyngeal maneuvers that decrease upper esophageal sphincter pressure.

            Rumination responds to increased personal attention and negative reinforcement. Chronic rumination may result in malnutrition, electrolyte disturbances, and esophagitis and is associated with a mortality rate of 15% to 25%.

            Achalasia is characterized by increased lower esophageal pressure, absent or incomplete relaxation of the lower esophageal sphincter, and defective esophageal peristalsis and megaesophagus. Symptoms are insidious in onset and include vomiting, dysphagia, weight loss, slow eating, and failure to thrive. In younger children, coughing, choking, and recurrent pneumonia may be more prominent.

            Gastric outlet obstruction presents with forceful nonbilious emesis, anorexia, and weight loss. Abdominal pain and distension may be noted.

            Sandifer syndrome is associated with reflux and is characterized by abnormal movement of the head and neck that results in unusual posturing. It usually consists of sudden extension of the head and neck into the position of opisthotonos. The movement is not related to the activity, but typically it resolves during sleep. Sandifer syndrome is thought to result in enhanced esophageal clearance of refluxed material.

            Many infants who have physiologic gastroesophageal reflux (GER) manifest no symptoms other than emesis and may appear to ruminate. Dysphagia for both solids and liquids may occur in older children. GER occurs in children who have rumination and vice versa, but GER is not associated with repetitive contractions of the abdominal musculature and often results in irritability rather than a calming effect.

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Q 4

A 12-year-old child is brought to the emergency department for evaluation of hematochezia. Physical examination reveals pallor, tachycardia, and hypotension, but no hepatosplenomegaly or abdominal tenderness.

After obtaining laboratory tests, the MOST appropriate next step in management is:

A. abdominal ultrasonography

B.  emergent colonoscopy

C.  Meckel scan

D.  placement of a nasogastric tube

E.  upper gastrointestinal radiographic series

Answer

D

In the acutely bleeding patient, assessment and data collection must occur simultaneously with stabilization and initial management. All blood or blood-like material passed from the rectum should be tested initially to confirm that it is, in fact, blood. Previous ingestion of cherry or strawberry candies, Popsicles®, and medications containing bismuth salts can mimic the appearance of blood.

            Because the distinction between upper and lower gastrointestinal bleeding is important in the management of the patient, determining the level of the hemorrhage is essential. Thus, after stabilizing the patient, the first diagnostic procedure in any type of gastrointestinal bleeding should be passage of a nasogastric tube. The presence of esophageal varices is not a contraindication to the passage of this tube.

            Blood losses from the upper gastrointestinal tract are more severe than from the lower gastrointestinal tract. Normally, upper gastrointestinal tract bleeding is associated with dark tarry stools (melena). However, bright red rectal bleeding may be of upper gastrointestinal origin in infants who have rapid intestinal transit (hematochezia) and in older children who have major gastrointestinal hemorrhage. The presence of borborygmi (the result of intestinal irritation by intraluminal blood) and an elevated serum blood urea nitrogen concentration (the result of reabsorbed nitrogen from the gastrointestinal tract) in these patients may suggest an upper gastrointestinal source of bleeding.

            Nasogastric aspirate that contains blood correctly identifies the presence of a lesion proximal to the ligament of Treitz in up to 90% of cases. The presence of small amounts of blood in the aspirate from the nasogastric tube may be difficult to interpret. If the blood clears rapidly from the tubing and does not reaccumulate, it is likely the result of trauma due to tube passage. If fresh blood is identified, aspiration of the gastric contents can be completed before upper endoscopy is performed. Upper endoscopy will localize the site of bleeding in more than 90% of such patients.

            If the nasogastric return is clear or bilious, the source of bleeding is not in the nasopharynx, esophagus, stomach, or proximal duodenum, and the nasogastric tube can be removed.

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Q 5

The mother of a 2-year-old boy saw him swallow a dime. Upon arrival at the emergency department, the boy appears well and is not in respiratory distress.

Of the following, the MOST appropriate evaluation is:

A. chest and abdominal radiography

B.  close observation

C.  emergent endoscopy

D.  inspection of the stool for the coin

E.   trial of drinking apple juice

Answer

A

Chest radiography is recommended for all children who have swallowed coins, although recent data suggest that most asymptomatic children do not receive a radiograph following an ingestion. In the esophagus, the flat surface of the coin will be seen on the anteroposterior view, and the edge will be seen on the lateral view. The opposite will be true for coins present in the trachea. The presence of a coin in the stomach allows for expectant observation in the absence of abdominal pain and vomiting. The absence of a coin on abdominal radiography that includes the esophagus suggests that the history of ingestion was in error.

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Q6 :

A 3-year-old child has a history of abdominal distension and rectal prolapse. Rectal examination reveals decreased anal tone and stool at the anal verge. Abdominal radiography shows a distended large intestine and stool in the distal colon and rectum.

Of the following, the MOST likely cause of this child's symptoms is:

A.  cystic fibrosis

B.  functional constipation

C.  Hirschsprung disease

D.  hypothyroidism

E.   intestinal pseudo-obstruction

Answer

B

            The differential diagnosis of constipation in the young child includes: psychogenic factors (eg, abuse, coercive toilet training, toilet phobia), motility disorders (eg, Hirschsprung disease, intestinal pseudo-obstruction), dehydration and malnutrition, anorectal anatomic abnormalities, endocrine or metabolic dysfunction, neuropathic conditions (eg, myelomeningocele), abnormal abdominal musculature, connective tissue disorders, pharmacologic ingestion, and botulinism.

Voluntary stool withholding is due to fear of defecation (often associated with discomfort). Instead of relaxing the pelvic floor during a valsalva maneuver, the patient contracts the gluteal muscles in an attempt to avoid defecation. Eventually, the urge to defecate is lost. Functional fecal retention typically occurs during toilet training and again upon entrance to school. Some children refuse to sit on the toilet for reasons other than rectal discomfort. In older children, the urge to defecate may be suppressed due to the unattractiveness of the school toilet or an unwillingness to interrupt an activity in which they are involved. Whatever the cause, failure to defecate is associated with fecal accumulation in the rectum, leading to abdominal pain and distension and a deterioration of mood and appetite.

Although cystic fibrosis can present with constipation and rectal prolapse, the disorder is much less common than functional constipation. In most children, prolapse is associated with malnutrition rather than due to cystic fibrosis alone. In patients who have rectal prolapse, a sweat chloride analysis may be useful. 

Hirschsprung disease and hypothyroidism rarely cause rectal prolapse and present with normal or increased rectal tone. In Hirschsprung disease, the rectal vault is empty. Intestinal pseudo-obstruction (primary intestinal myopathy or neuropathy) can present in a similar fashion to functional constipation, but it is a rare disorder. Abdominal radiographs reveal signs of obstruction, including distended bowel loops with air-fluid levels

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Q 7:

.A 2-year-old boy is placed on oral antibiotic therapy to treat otitis media. Three weeks later he becomes febrile (temperature, 102°F [38.9°C]) and develops abdominal distension and tenderness and bloody diarrhea.

Of the following, the MOST likely etiology of his bloody diarrhea is an infection caused by:

A. Campylobacter jejuni

B.  Clostridium difficile

C.  enteropathogenic Escherichia coli

D.  Salmonella sp

E.  Shigella sp

Answer

B

Pseudomembranous colitis can develop after the administration of any antibiotic, even agents that are used to treat this disorder. Amoxicillin, because of its frequent use in children, is responsible for most cases in the pediatric population. Cephalosporins and clindamycin also are associated commonly with its development.

The spectrum of C difficile-associated diseases in children is variable, ranging from acute, self-limited diarrhea to toxic megacolon. The diarrhea typically begins within 10 days of antibiotic administration, although some cases begin as late as 6 weeks later. Approximately 10% of children who are infected with C difficile will develop pseudomembranous colitis, which is characterized by the sudden onset of severe diarrhea and crampy abdominal pain. Symptoms often begin within 1 week of the administration of an antibiotic. Tenesmus, vomiting, and high fever complicate the clinical course. Abdominal distension and tenderness are found upon physical examination. 

Lower gastrointestinal bleeding is often associated with pseudomembranous colitis, as are electrolyte imbalances, leukocytosis, metabolic acidosis, and hypoproteinemia. Colonoscopy reveals small plaques of yellow-white exudates (pseudomembranes), petechiae, and friability. Toxic megacolon, characterized by colonic dilation, localized peritonitis, septicemia, and renal failure, is a severe manifestation of infection with C difficile. Other clinical manifestations of C difficile-associated infection include acute self-limited diarrhea, failure to thrive due to chronic infection without colitis, and an acute flare of inflammatory bowel disease without prior use of antibiotic therapy.

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Q 8

A 15-year-old boy comes to your office for evaluation of vomiting. He explains that the episodes occur every 3 months and last 48 hours. The emesis initially contains food particles, but soon becomes bilious. After 24 hours of vomiting, he becomes dehydrated and requires administration of intravenous fluids in the emergency department. Between the episodes, he is asymptomatic.

Of the following, the MOST likely etiology of this vomiting is:

A.  cyclic vomiting

B.   food allergy

C.   giardiasis

D.   gluten sensitivity

E.    recurrent viral gastroenteritis

Answer

A

Cyclic vomiting is characterized by paroxysms of severe vomiting without apparent cause separated by periods of complete health. Typically, cyclic vomiting begins in a child between 3 and 7 years of age. A family history of migraine or irritable bowel syndrome often is noted. 

 Intense vomiting begins spontaneously, with nausea, lethargy, fever, and headache preceding the onset of the emesis. The episodes last up to 48 hours (although some lasting 5 to 7 days have been reported), with 4 to 12 episodes per hour, and end suddenly, often after a period of sleep. Two thirds of the children become dehydrated and require intravenous fluid therapy, such as the boy in the vignette. Each patient has a stereotypic pattern of time of onset and triggering events (eg, stress or excitement), length of vomiting, and interval between the attacks. Episodes often begin during the night or upon arising in the morning. 

The evaluation of a child who has cyclic vomiting should focus on eliminating gastrointestinal anomalies and inflammation; renal, metabolic, and central nervous system pathologies; and endocrine disorders. 

Evaluation may include magnetic resonance imaging or computed tomographic scan of the head and abdomen; electroencephalography; and measurement of serum and urine organic and amino acids, serum H pylori titer, and morning cortisol levels.

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Q 9

A 3-month-old male infant is jaundiced and febrile. He underwent a Kasai procedure for biliary atresia 1 month ago. Laboratory tests reveal a white blood cell count of 15,300/cu mm (15.3 x 109/L), a total bilirubin concentration of 7.0 mg/dL (119.7 mcmol/L), and a direct bilirubin of 3.5 mg/dL (59.9 mcmol/L(.

Of the following, the MOST likely cause of his symptoms is:

A.         ascending cholangitis

B. biliary obstruction

C. Caroli disease

D.  infectious hepatitis

E.  sclerosing cholangitis

Answer

A

Bacterial ascending cholangitis is the most common complication following a portoenterostomy, occurring in 50% to 70% of infants in whom bile flow is established. It typically presents within the first 2 years after surgery. Affected infants become febrile and manifest leukocytosis and an increased erythrocyte sedimentation rate, as described for the infant in the vignette. An increase in serum bilirubin (both total and direct) is found in 75% of children; serum transaminase concentrations may increase late in the course of infection. The diagnosis is confirmed by demonstration of the pathogen in blood (uncommon) or hepatic tissue culture. The cholangitis interferes with bile flow and results in progressive hepatic fibrosis, portal hypertension, gastrointestinal bleeding, ascites, and liver failure. The most common pathogens are gram-negative rods, although polymicrobial infection with anaerobic bacteria also can occur. Treatment of ascending cholangitis involves broad-spectrum antibiotics, including aminoglycosides and cephalosporins

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Q 10


A 13-month-old infant presents with a 1-month history of chronic diarrhea and weight loss. The baby tolerated cow milk formula well, but the diarrhea began around the time he was transitioned to whole milk. There is a family history of multiple food allergies. Physical examination demonstrates a thin infant whose weight is at the 10th percentile and height is at the 50th percentile. Stool cultures for enteric pathogens and viruses are negative. Results of complete blood count, chemistries, and serum immunoglobulin (Ig) A measurement are normal. Celiac serologies demonstrate a positive antigliadin IgG, negative antiendomysial antibodies, and negative tissue transglutaminase antibody. A small bowel biopsy demonstrates increased cellularity of the intestinal lamina propria and partial villous atrophy.

Of the following, a TRUE statement regarding the patient’s small bowel biopsy is that the findings

A. are diagnostic for giardiasis
B. are nonspecific
C. are pathognomonic for rotavirus infection
D. exclude celiac disease
E. rule out milk protein allergy

Answer

B


The patient described in the vignette underwent a small bowel biopsy to evaluate chronic
diarrhea and weight loss. Although the patient has a positive antigliadin immunoglobulin G, the
antibodies that are most sensitive and specific for celiac disease (anti-tissue transglutaminase
and anti-endomysial) are both negative. The biopsy findings described in the vignette suggest
intestinal injury, but are nonspecific. They do not distinguish between celiac disease, allergy, and
infectious enteritis.