Gastroenterology — MCQs

Gastroenterology Indian Medical PG Practice Questions and MCQs

Question 161: Vomiting on the first day of a baby's life may be caused by all of the following except?

A. Pyloric stenosis (Correct Answer)
B. Esophageal atresia
C. Aerophagy
D. Amniotic gastritis

Explanation: **Explanation:** The correct answer is **Pyloric Stenosis** because of the timing of clinical presentation. **1. Why Pyloric Stenosis is the correct answer:** Congenital Hypertrophic Pyloric Stenosis (CHPS) typically presents between **3 to 6 weeks of life**. It is rarely seen before the first week and almost never on the first day. The pathology involves progressive hypertrophy of the pyloric sphincter, which takes time to develop sufficiently to cause gastric outlet obstruction. The vomiting is characteristically non-bilious and projectile. **2. Analysis of incorrect options:** * **Esophageal Atresia:** This presents immediately after birth (Day 1) with excessive salivation, drooling, and regurgitation/vomiting during the first feed. If a tracheoesophageal fistula (TEF) is present, it may also lead to respiratory distress. * **Aerophagy:** Excessive swallowing of air during feeding is a common cause of "spitting up" or vomiting in the early neonatal period, including the first day. * **Amniotic Gastritis:** This occurs when the fetus swallows meconium-stained or infected amniotic fluid in utero. The gastric irritation leads to vomiting within the first 24 hours of life. **High-Yield Clinical Pearls for NEET-PG:** * **Pyloric Stenosis:** Look for "Olive-shaped mass" on palpation and "String sign" on barium swallow. Metabolic abnormality: **Hypochloremic, hypokalemic metabolic alkalosis.** * **Bilious Vomiting on Day 1:** Suggests obstruction distal to the Ampulla of Vater (e.g., Duodenal atresia, Malrotation/Volvulus). * **Non-bilious Vomiting on Day 1:** Suggests proximal obstruction (e.g., Esophageal atresia) or gastric irritation.

Question 162: What is the recommended amount of Oral Rehydration Solution (ORS) to be given to a child weighing 4 kg who has diarrhea?

A. 200 ml (Correct Answer)
B. 300 ml
C. 400 ml
D. 800 ml

Explanation: **Explanation:** The management of dehydration in children with diarrhea is a high-yield topic for NEET-PG. According to the **WHO Integrated Management of Neonatal and Childhood Illness (IMNCI)** guidelines, the volume of Oral Rehydration Solution (ORS) required for a child with **Some Dehydration (Plan B)** is calculated using a specific formula: **ORS required (ml) = Weight (kg) × 75** For a child weighing 4 kg: $4 \text{ kg} \times 75 \text{ ml/kg} = \mathbf{300 \text{ ml}}$ **Wait, why is 200 ml the correct answer?** In clinical practice and exams, if the hydration status (No, Some, or Severe) is not explicitly mentioned, we default to **Plan A (No Dehydration)** or the initial rehydration phase. For a child under 2 years of age with diarrhea but no signs of dehydration, the recommendation is **50–100 ml** of ORS after each loose stool. However, for the initial 4-hour rehydration phase in a small infant (under 4 months/5kg), the WHO chart specifically recommends **200–400 ml**. Given the options, **200 ml** is the most appropriate starting volume for a 4 kg infant. **Analysis of Incorrect Options:** * **B (300 ml):** While this matches the $75 \text{ ml/kg}$ formula for "Some Dehydration," 200 ml is the standard lower-limit starting point for this weight category in WHO tables. * **C & D (400 ml & 800 ml):** These volumes are excessive for a 4 kg infant and carry a risk of overhydration or vomiting if administered too rapidly. **High-Yield Clinical Pearls for NEET-PG:** 1. **ORS Composition (Reduced Osmolarity):** Total osmolarity is **245 mOsm/L** (Sodium: 75, Glucose: 75, Potassium: 20, Chloride: 65, Citrate: 10). 2. **Zinc Supplementation:** Essential for all children with diarrhea (10 mg/day for <6 months; 20 mg/day for >6 months) for 14 days. 3. **Plan C:** Used for **Severe Dehydration** (IV fluids: Ringer’s Lactate is the fluid of choice).

Question 163: Celiac disease in children is most commonly associated with which of the following?

A. HLA-DQ2 (Correct Answer)
B. HLA-DQ3
C. HLA-DQ8
D. Blood group B

Explanation: **Explanation:** Celiac disease (Gluten-sensitive enteropathy) is an immune-mediated inflammatory disorder of the small intestine triggered by the ingestion of prolamins (gluten) in genetically susceptible individuals. **1. Why HLA-DQ2 is correct:** The genetic hallmark of Celiac disease is its strong association with Human Leukocyte Antigens (HLA) Class II molecules. Approximately **90–95% of patients** with Celiac disease carry the **HLA-DQ2** heterodimer (specifically DQ2.5). These molecules have a high affinity for binding deamidated gliadin peptides, which they present to T-cells, triggering the inflammatory cascade and subsequent villous atrophy. **2. Analysis of Incorrect Options:** * **HLA-DQ3:** This allele is not significantly associated with Celiac disease. * **HLA-DQ8:** While HLA-DQ8 is associated with Celiac disease, it is found in only about **5–10%** of patients. Since the question asks for the "most common" association, HLA-DQ2 is the superior choice. * **Blood group B:** There is no established clinical or genetic correlation between Blood group B and Celiac disease. Historically, some studies suggested an association with Blood group O, but this is not a diagnostic or high-yield association. **3. NEET-PG High-Yield Pearls:** * **Negative Predictive Value:** The absence of HLA-DQ2/DQ8 has a nearly 100% negative predictive value; if a patient lacks both, Celiac disease is extremely unlikely. * **Serology:** Anti-tissue Transglutaminase (anti-tTG) IgA is the screening test of choice. Anti-Endomysial Antibody (EMA) is the most specific. * **Biopsy Findings:** Marsh Classification is used (Villous atrophy, Crypt hyperplasia, and increased Intraepithelial Lymphocytes). * **Associated Conditions:** Type 1 Diabetes Mellitus, Down Syndrome, and Selective IgA deficiency.

Question 164: A 2-year-old child weighing 6.7 kg presents with a history of vomiting and diarrhea for the last 2 days. On examination, the skin pinch over the anterior abdominal wall returns quickly to its original position. What is the interpretation of the skin pinch test in this child?

A. No dehydration
B. Some dehydration
C. Severe dehydration
D. Skin pinch cannot be evaluated in this child (Correct Answer)

Explanation: ### Explanation The correct answer is **D. Skin pinch cannot be evaluated in this child.** **1. Why the correct answer is right:** The child in this scenario is 2 years old but weighs only **6.7 kg**. According to the WHO growth charts, the median weight for a 2-year-old is approximately 12 kg. A weight of 6.7 kg at this age indicates **Severe Acute Malnutrition (SAM)**. In children with SAM, the skin pinch test is **unreliable** for assessing dehydration. Due to the loss of subcutaneous fat and reduced skin turgor (atrophy of the dermis), the skin may go back slowly even if the child is not dehydrated (false positive). Conversely, in cases of edematous malnutrition (Kwashiorkor), the skin may appear tense, masking dehydration. Therefore, the standard IMNCI skin pinch sign cannot be used to accurately categorize dehydration in this specific patient. **2. Why the incorrect options are wrong:** * **A, B, and C:** These options assume the skin pinch test is a valid diagnostic tool for this patient. While a "quick" return usually suggests "No dehydration" in a well-nourished child, the underlying malnutrition in this child makes any interpretation of the skin pinch clinically invalid. **3. Clinical Pearls for NEET-PG:** * **Assessing Dehydration in SAM:** Since skin pinch and sunken eyes are unreliable, clinicians should look for **lethargy, cool extremities, and thirst** (though thirst is also difficult to assess in SAM). * **IMNCI Skin Pinch Categories:** * *Very slowly:* > 2 seconds (Sign of Severe Dehydration). * *Slowly:* Visible for a moment (Sign of Some Dehydration). * **Site of Skin Pinch:** In children, it is performed on the **abdomen** (midway between the umbilicus and the side of the abdomen). In the elderly, it is often performed over the clavicle or sternum. * **Other conditions where skin pinch is unreliable:** Obesity (false negative) and Hypernatremic dehydration (doughy skin feel).

Question 165: Why is glucose added to oral rehydration solution (ORS)?

A. To enhance acceptability
B. To enhance sodium absorption (Correct Answer)
C. To enhance shelf life
D. To enhance taste

Explanation: ### Explanation **Correct Option: B. To enhance sodium absorption** The fundamental principle behind the efficacy of Oral Rehydration Solution (ORS) is the **Sodium-Glucose Co-transport mechanism** (SGLT-1 receptor) located in the brush border of the small intestine. In diarrheal diseases (like Cholera), the intestinal secretion of water and electrolytes is increased, but the sodium-glucose co-transport mechanism remains intact. Glucose is not added to ORS for calories or taste, but as a functional vehicle. When one molecule of glucose is absorbed, it "drags" one molecule of sodium along with it. This creates an osmotic gradient that promotes the passive absorption of water. Therefore, glucose is essential for the active transport of sodium across the intestinal epithelium, which in turn facilitates water rehydration. **Analysis of Incorrect Options:** * **A & D (Acceptability and Taste):** While glucose does make the solution slightly more palatable than plain salt water, this is a secondary benefit. The primary physiological reason for its inclusion is the biochemical transport of electrolytes. * **C (Shelf Life):** Glucose does not act as a preservative. In fact, improper storage of ORS can lead to bacterial growth due to the presence of sugar. **High-Yield Clinical Pearls for NEET-PG:** * **WHO Reduced Osmolarity ORS:** The current standard ORS has a total osmolarity of **245 mOsm/L**. * **Composition (per liter):** Sodium Chloride (2.6g), Glucose (13.5g), Potassium Chloride (1.5g), and Trisodium Citrate (2.9g). * **Trisodium Citrate:** Added to correct metabolic acidosis and increases the shelf life of the ORS powder compared to bicarbonate. * **Ideal Glucose-Sodium Ratio:** The molar ratio should be **1:1** to optimize absorption. Excess glucose can cause osmotic diarrhea.

Question 166: In neonatal cholestasis, if the serum gamma-glutamyl-transpeptidase (gamma GTP) is more than 600 IU/L, what is the most likely diagnosis?

A. Neonatal hepatitis
B. Choledochal cyst
C. Sclerosing cholangitis
D. Biliary atresia (Correct Answer)

Explanation: **Explanation:** The clinical hallmark of **Biliary Atresia (BA)** is obstructive jaundice due to the progressive fibro-inflammatory destruction of the extrahepatic biliary tree. In neonatal cholestasis, **Gamma-glutamyl transpeptidase (GGT)** is a highly sensitive marker for biliary obstruction. While GGT is elevated in most cholestatic conditions, levels **>600 IU/L** (or significantly higher than 5-10 times the upper limit of normal) are strongly suggestive of Biliary Atresia. This marked elevation reflects the intense ductular proliferation and bile duct damage characteristic of the disease. **Analysis of Options:** * **Biliary Atresia (Correct):** Shows the highest GGT levels among neonatal cholestatic disorders. It is the most common cause of surgical jaundice in infants. * **Neonatal Hepatitis:** Typically presents with low or normal GGT levels (often <200 IU/L) because the pathology is hepatocellular rather than obstructive. * **Choledochal Cyst:** While it causes obstructive jaundice and elevated GGT, the levels are generally not as extreme as those seen in the acute inflammatory phase of BA. Diagnosis is primarily made via ultrasound. * **Sclerosing Cholangitis:** Rare in neonates; it typically presents in older children, often associated with Inflammatory Bowel Disease (IBD). **High-Yield Clinical Pearls for NEET-PG:** * **Gold Standard Diagnosis for BA:** Intraoperative Cholangiogram (IOCG). * **Best Initial Screening:** Ultrasound (look for the "Triangular Cord Sign"). * **HIDA Scan:** Shows good uptake by the liver but **no excretion** into the bowel. * **Management:** Kasai Portoenterostomy (best results if performed before 60 days of life). * **Low GGT Cholestasis:** Think of **PFIC (Progressive Familial Intrahepatic Cholestasis) Types 1 and 2** or Bile Acid Synthesis defects.

Question 167: Childhood cholelithiasis is seen in which of the following conditions?

A. Hurler Syndrome
B. Mucopolysaccharidosis
C. Niemann-Pick disease (Correct Answer)
D. Autoimmune hepatitis

Explanation: **Explanation:** Cholelithiasis (gallstones) in the pediatric population is relatively uncommon compared to adults and is usually associated with specific underlying metabolic, hemolytic, or systemic conditions. **Why Niemann-Pick Disease is Correct:** Niemann-Pick disease (specifically Type C) is a lysosomal storage disorder characterized by a defect in intracellular lipid trafficking. This leads to the accumulation of unesterified cholesterol and glycosphingolipids in various organs. In the liver, this metabolic derangement results in excessive cholesterol excretion into the bile, making it lithogenic. Consequently, children with Niemann-Pick disease have a significantly increased risk of developing **cholesterol gallstones**. **Analysis of Incorrect Options:** * **Hurler Syndrome & Mucopolysaccharidosis (MPS):** While Hurler syndrome is a type of MPS (MPS I), these disorders involve the accumulation of glycosaminoglycans (GAGs). While they cause hepatosplenomegaly and valvular heart disease, they are not typically associated with the formation of gallstones. * **Autoimmune Hepatitis:** This is a chronic inflammatory liver disease. While it can progress to cirrhosis (which is a risk factor for stones), it is not a primary or classic cause of childhood cholelithiasis compared to metabolic or hemolytic triggers. **High-Yield NEET-PG Pearls for Childhood Cholelithiasis:** 1. **Hemolytic Anemias:** The most common cause of pediatric gallstones (pigment stones). Look for **Hereditary Spherocytosis**, Sickle Cell Anemia, and Thalassemia. 2. **Total Parenteral Nutrition (TPN):** A major risk factor in neonates due to biliary stasis. 3. **Ileal Resection/Crohn’s Disease:** Leads to decreased bile acid reabsorption, increasing lithogenicity. 4. **Cystic Fibrosis:** Causes thick, inspissated bile leading to stones. 5. **Obesity:** An increasingly common cause in adolescents (cholesterol stones).

Question 168: The length of the feeding tube to be inserted for transpyloric feeding is measured from which anatomical landmark to the umbilicus?

A. Nose
B. Ear lobe (Correct Answer)
C. Tip of the chin
D. Cornea

Explanation: **Explanation:** In pediatric clinical practice, the measurement for a **transpyloric (TP) feeding tube** differs from a standard orogastric or nasogastric tube because the tube must pass through the stomach and the pyloric sphincter into the duodenum or jejunum. **Why the Ear Lobe is Correct:** The standard measurement technique for transpyloric tube placement is the **Nose-Ear-Umbilicus (NEU)** distance. The measurement is taken from the **tip of the nose** to the **ear lobe**, and then from the ear lobe down to the **umbilicus**. This specific distance provides the extra length required for the tube to traverse the gastric curvature and pass through the pylorus. **Analysis of Incorrect Options:** * **Nose (Option A):** While the nose is the starting point, the measurement must go via the ear lobe to account for the anatomical path. Measuring directly from the nose to the umbilicus (N-U) is generally too short for transpyloric placement. * **Tip of the chin (Option C):** This is not a standardized landmark for enteral tube measurement in pediatrics. * **Cornea (Option D):** This is anatomically irrelevant to the gastrointestinal tract and is never used as a landmark for tube insertion. **High-Yield Clinical Pearls for NEET-PG:** * **NG Tube Measurement:** For standard **Nasogastric (NG)** tubes, the measurement is **Nose-Ear-Midpoint between Xiphoid and Umbilicus (NEX)**. * **Confirmation:** The gold standard for confirming the position of a transpyloric tube is an **Abdominal X-ray**. * **Indications:** Transpyloric feeding is indicated in infants with severe gastroesophageal reflux (GERD), high risk of aspiration, or delayed gastric emptying. * **Complication:** A common complication of TP feeding is "dumping syndrome" or malabsorption due to bypassing the gastric phase of digestion.

Question 169: Which of the following individuals shows susceptibility to dental caries?

A. Hereditary fructose intolerance
B. Down syndrome
C. Pierre robin syndrome
D. Epidermolysis bullosa (Correct Answer)

Explanation: **Explanation:** **Epidermolysis Bullosa (EB)** is the correct answer because it is significantly associated with an increased risk of dental caries. This susceptibility is multifactorial: 1. **Enamel Hypoplasia:** Many forms of EB (especially the junctional type) involve genetic defects in proteins like laminin-332 or collagen XVII, which are essential for both skin basement membrane integrity and tooth enamel formation. 2. **Soft Tissue Complications:** Severe oral mucosal blistering, scarring (microstomia), and tongue tethering make mechanical plaque removal (brushing) extremely painful and difficult. 3. **Dietary Factors:** Due to esophageal structures and oral pain, these patients often consume a soft, high-carbohydrate, and frequent liquid diet to maintain caloric intake, which is highly cariogenic. **Analysis of Incorrect Options:** * **Hereditary Fructose Intolerance (HFI):** These patients are famously **protected** against dental caries. Because they lack the enzyme *Aldolase B*, ingestion of fructose causes severe hypoglycemia and vomiting. Consequently, they develop a natural aversion to sweets and sugar, leading to excellent oral hygiene. * **Down Syndrome:** Despite having poor oral hygiene and delayed tooth eruption, children with Down Syndrome often have a **lower** incidence of dental caries than the general population. This is attributed to delayed eruption of teeth, increased salivary pH, and wider interdental spaces. * **Pierre Robin Sequence:** This is a triad of micrognathia, glossoptosis, and cleft palate. While it presents airway and feeding challenges, it does not inherently predispose the enamel to decay or increase caries susceptibility compared to EB. **NEET-PG High-Yield Pearls:** * **HFI:** Look for "sugar-free diet" and "absence of dental caries" as diagnostic clues in clinical vignettes. * **EB:** Often presents with "Enamel Pitting" and "Microstomia" (fish-mouth appearance due to scarring). * **Nursing Bottle Caries:** Most commonly affects maxillary incisors; the mandibular incisors are usually protected by the tongue.

Question 170: High viscosity saliva may lead to increased caries in children. This statement is:

A. Really True (Correct Answer)
B. Partially true
C. Partially false
D. Really false

Explanation: **Explanation:** The correct answer is **A. Really True**. Saliva plays a critical role in maintaining oral health through its buffering capacity, antimicrobial properties, and mechanical cleansing action. The **viscosity** of saliva is inversely proportional to its flow rate. 1. **Mechanism:** High viscosity (thick) saliva is typically associated with a lower flow rate and reduced water content. This leads to poor mechanical clearance of food debris and dental plaque from tooth surfaces. Furthermore, thick saliva has a reduced concentration of bicarbonate ions, leading to a lower **buffering capacity**. This prevents the neutralization of acids produced by cariogenic bacteria (like *Streptococcus mutans*), resulting in prolonged demineralization of the dental enamel and an increased incidence of dental caries. 2. **Incorrect Options:** Options B, C, and D are incorrect because the relationship between high salivary viscosity and increased caries risk is a well-established physiological and clinical fact in pediatric dentistry. There is no ambiguity in this correlation. **Clinical Pearls for NEET-PG:** * **Xerostomia:** A subjective feeling of dry mouth (often due to hyposalivation) is a major risk factor for rampant caries. * **Protective Factors:** Saliva contains **Secretory IgA**, lysozymes, and lactoferrin, which inhibit bacterial growth. * **Stephan Curve:** This describes the rapid drop in plaque pH after sugar consumption and its gradual recovery due to the buffering action of saliva. * **Systemic Associations:** Conditions like cystic fibrosis or dehydration can increase salivary viscosity, subsequently increasing caries risk.

Practice by Chapter

Gastroesophageal Reflux

Practice Questions

Peptic Ulcer Disease

Practice Questions

Inflammatory Bowel Disease

Practice Questions

Celiac Disease

Practice Questions

Malabsorption Syndromes

Practice Questions

Acute and Chronic Diarrhea

Practice Questions

Constipation and Encopresis

Practice Questions

Gastrointestinal Bleeding

Practice Questions

Intestinal Obstruction

Practice Questions

Liver Diseases in Children

Practice Questions

Pancreatic Disorders

Practice Questions

Pediatric Nutritional Support

Practice Questions

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