Gastroenterology Practice Questions

Q: At what age does a baby with congenital hypertrophic pyloric stenosis typically show symptoms?

Between the 3rd and 4th week of life. **Explanation:** **Congenital Hypertrophic Pyloric Stenosis (CHPS)** is characterized by hypertrophy and hyperplasia of the muscular layers of the pylorus, leading to a functional gastric outlet obstruction. 1. **Why Option C is Correct:** Although the condition is termed "congenital," the hypertrophy is progressive rather than present at birth. Symptoms typically manifest between **3 to 6 weeks of life** (most commonly during the 3rd or 4th week). It takes this period for the pyloric muscle to thicken sufficiently to cause a near-complete obstruction, resulting in the classic symptom of **non-bilious, projectile vomiting** immediately after feeds. 2. **Why Other Options are Incorrect:** * **Option A & B:** CHPS is almost never symptomatic at birth or in the first week. Vomiting in the first 24–48 hours usually suggests intestinal atresia or malrotation. * **Option D:** While symptoms can occasionally persist or start in the second month, the peak incidence and classic presentation window for board exams is the 3rd to 6th week. **High-Yield Clinical Pearls for NEET-PG:** * **Epidemiology:** Most common in **first-born male** infants; associated with maternal **erythromycin** use. * **Clinical Sign:** A palpable, olive-shaped mass in the epigastrium (best felt after vomiting). * **Metabolic Profile:** **Hypochloremic, hypokalemic, metabolic alkalosis** with paradoxical aciduria (a favorite NEET-PG question). * **Diagnosis:** Ultrasound is the gold standard (Pyloric muscle thickness >4mm or length >14mm). * **Management:** Initial step is fluid resuscitation (Normal Saline); definitive treatment is **Ramstedt’s Pyloromyotomy**.

Q: What is the most common cause of colonic obstruction in neonates?

Aganglionic colon. **Explanation:** The correct answer is **Aganglionic colon**, also known as **Hirschsprung Disease (HD)**. It is characterized by the congenital absence of ganglion cells in the submucosal (Meissner's) and myenteric (Auerbach's) plexuses, starting from the internal anal sphincter and extending proximally. This leads to a functional obstruction because the affected segment cannot relax, resulting in proximal colonic dilatation. It is the most common cause of lower intestinal (colonic) obstruction in neonates, typically presenting with failure to pass meconium within the first 48 hours of life. **Analysis of Incorrect Options:** * **Meconium ileus:** This is the most common cause of **small bowel** obstruction in newborns (often associated with Cystic Fibrosis), where inspissated meconium obstructs the terminal ileum, not the colon. * **Ileal atresia:** This is a common cause of neonatal intestinal obstruction, but it occurs in the **small intestine**. It results from an in-utero vascular accident. * **Volvulus:** While Midgut Volvulus (due to malrotation) is a surgical emergency, it primarily affects the small bowel and is less common than Hirschsprung disease as an initial cause of colonic obstruction. **High-Yield Clinical Pearls for NEET-PG:** * **Gold Standard Diagnosis:** Rectal Suction Biopsy (shows absence of ganglion cells and hypertrophied nerve bundles). * **Radiology:** Barium enema shows a "transition zone" (narrow distal segment and dilated proximal segment). * **Associated Condition:** Down Syndrome (Trisomy 21) is seen in approximately 10% of cases. * **Initial Sign:** Delayed passage of meconium (>24-48 hours) and a "blast sign" (explosive release of gas/stool) on digital rectal examination.

Q: A 3-week-old boy presents with projectile, non-bilious vomiting after feeding. Physical examination reveals a firm, olive-like mass in the epigastric region. Ultrasound shows thickened pyloric muscle. What is the most likely pathological finding if the pyloric muscle is biopsied?

Hypertrophy of the muscularis propria. **Explanation:** The clinical presentation of a 3-week-old male with **projectile, non-bilious vomiting** and a palpable **"olive-shaped" mass** in the epigastrium is pathognomonic for **Infantile Hypertrophic Pyloric Stenosis (IHPS)**. **Why Option A is correct:** The underlying pathology of IHPS is the **hypertrophy (and hyperplasia)** of the circular muscle fibers of the **muscularis propria** in the pylorus. This thickening narrows the pyloric canal and lengthens it, creating a functional gastric outlet obstruction. On ultrasound, a muscle thickness >3 mm or a pyloric length >14 mm is diagnostic. **Why the other options are incorrect:** * **Option B:** Inflammation is not the primary process; IHPS is a structural/mechanical hypertrophy, not an infectious or inflammatory "itis." * **Option C:** While gastric dilatation occurs secondary to the obstruction, it is a *consequence* of the pathology, not the pathological change within the pyloric muscle itself. * **Option D:** The obstruction occurs at the pylorus (the sphincter between the stomach and duodenum), not within the duodenum itself. Duodenal atresia/stricture typically presents with *bilious* vomiting. **NEET-PG High-Yield Pearls:** * **Metabolic Profile:** Classic finding is **Hypochloremic, Hypokalemic, Metabolic Alkalosis** with paradoxical aciduria. * **Demographics:** Most common in first-born males; associated with **Erythromycin/Azithromycin** use in early infancy. * **Initial Management:** The priority is always **fluid resuscitation** (Normal Saline) and correction of electrolyte imbalances before surgery. * **Definitive Treatment:** **Ramstedt’s Pyloromyotomy** (longitudinal incision of the hypertrophied muscle while leaving the mucosa intact).

Q: An infant presented with failure to thrive, stridor, otitis media, and esophagitis. What is the most probable diagnosis?

Gastroesophageal reflux disease. **Explanation:** The clinical presentation of failure to thrive, respiratory symptoms (stridor), recurrent infections (otitis media), and esophagitis is classic for **Gastroesophageal Reflux Disease (GERD)** in infants. **Why GERD is the correct answer:** In infants, GERD occurs when the retrograde movement of gastric contents into the esophagus causes complications. * **Esophagitis:** Acid irritation leads to pain, irritability, and hematemesis. * **Failure to Thrive:** Caloric loss through vomiting and feeding aversion due to pain. * **Extra-esophageal manifestations:** Micro-aspiration or vagally mediated reflexes can cause **stridor**, wheezing, or chronic cough. Refluxate reaching the nasopharynx can cause Eustachian tube dysfunction, leading to **otitis media**. **Why other options are incorrect:** * **Tracheoesophageal fistula (TEF):** Usually presents in the immediate neonatal period with drooling, choking, and cyanosis during feeds. While it causes respiratory issues, it does not typically present as chronic failure to thrive with esophagitis in this pattern. * **Hypertrophic Pyloric Stenosis (HPS):** Characterized by non-bilious, **projectile vomiting** and a palpable "olive-shaped" mass. It typically presents at 3–6 weeks of age and leads to metabolic alkalosis, not stridor or otitis media. * **Duodenal Atresia:** Presents within the first 24–48 hours of life with **bilious vomiting** and a "double bubble" sign on X-ray. **NEET-PG High-Yield Pearls:** * **Sandifer Syndrome:** A specific manifestation of GERD in infants involving abnormal posturing (arching of the back and neck torsion) that mimics seizures. * **Gold Standard Diagnosis:** 24-hour esophageal pH monitoring (though clinical diagnosis is common). * **Management:** Conservative (thickened feeds, upright positioning) is first-line; PPIs are used for documented esophagitis.

Q: A newborn girl has not passed meconium for 48 hours, presents with abdominal distention and vomiting. What is the initial investigation of choice?

Lower GI contrast study. **Explanation:** The clinical presentation of delayed meconium passage (>24–48 hours), abdominal distention, and vomiting in a newborn suggests a distal intestinal obstruction. The two primary differentials are **Hirschsprung Disease (HD)** and **Meconium Ileus (MI)**. **Why Lower GI Contrast Study is the Initial Investigation:** A water-soluble contrast enema (Lower GI study) is the preferred initial diagnostic step because it serves both a diagnostic and potentially therapeutic purpose. * In **Hirschsprung Disease**, it reveals a "transition zone" (narrowed aganglionic segment with proximal dilation) and a reversed recto-sigmoid ratio. * In **Meconium Ileus**, it shows a "microcolon" and filling defects (meconium pellets). Gastrografin enemas can also help liquefy and flush out the inspissated meconium. **Analysis of Incorrect Options:** * **A. Manometry:** Anorectal manometry (showing absence of the recto-anal inhibitory reflex) is highly sensitive for HD but is technically difficult to perform and interpret in the first few days of life. It is usually done later. * **B & D. Genotyping and Serum Trypsin:** These are used to diagnose **Cystic Fibrosis (CF)**. While 90% of infants with Meconium Ileus have CF, these tests do not address the immediate anatomical obstruction and are not the "initial" step in an acute surgical presentation. **High-Yield Clinical Pearls for NEET-PG:** * **Gold Standard for HD:** Rectal Suction Biopsy (shows absence of ganglion cells and hypertrophied nerve bundles). * **X-ray finding:** "Soap bubble appearance" (Neuhauser sign) in the right iliac fossa is characteristic of Meconium Ileus. * **Rectal Exam:** In HD, a digital rectal exam often results in a "blast sign" (explosive release of gas and stool).

Q: A young boy presents with massive hematemesis. He had a fever for 15 days a few days back, which was treated with some drugs. Clinical examination reveals moderate splenomegaly. No other history is positive. What is the probable diagnosis?

Esophageal varices. **Explanation:** The clinical presentation of **massive hematemesis** associated with **splenomegaly** in a child is a classic indicator of **Portal Hypertension**, most commonly due to **Extrahepatic Portal Venous Obstruction (EHPVO)**. **Why Esophageal Varices is correct:** In children, EHPVO often follows an umbilical infection or a systemic febrile illness (as seen in this case). The fever likely led to dehydration or a prothrombotic state, causing portal vein thrombosis. This results in portal hypertension, leading to: 1. **Congestive Splenomegaly:** The spleen enlarges due to backed-up venous pressure. 2. **Esophageal Varices:** Portosystemic collaterals form; their rupture causes sudden, painless, massive hematemesis. The absence of jaundice or signs of liver failure (normal liver) further supports EHPVO over cirrhosis. **Why other options are incorrect:** * **Drug-induced gastritis:** While common after NSAID use for fever, it typically presents with coffee-ground emesis or melena and epigastric pain, but **never** with splenomegaly. * **Esophageal tear (Mallory-Weiss):** This follows forceful vomiting or retching. It does not explain the presence of splenomegaly. * **Bleeding duodenal ulcer:** This causes hematemesis and melena, usually associated with a history of dyspepsia. It does not cause splenomegaly. **Clinical Pearls for NEET-PG:** * **EHPVO** is the most common cause of massive upper GI bleed in children in India. * **Key Triad for EHPVO:** Massive hematemesis + Splenomegaly + Normal liver function tests (LFTs). * **Management:** Endoscopic Variceal Ligation (EVL) or Sclerotherapy is the acute treatment of choice. Propranolol is used for primary prophylaxis.

Q: If you suspect a child to have Congenital Hypertrophic Pyloric Stenosis clinically, what is the next best investigation?

USG. **Explanation:** **Congenital Hypertrophic Pyloric Stenosis (CHPS)** is characterized by hypertrophy of the pyloric sphincter muscle, leading to gastric outlet obstruction. **Why USG is the Correct Answer:** Ultrasonography (USG) is the **investigation of choice** because it is non-invasive, avoids radiation, and provides high sensitivity and specificity. It allows for direct measurement of the pyloric muscle. The diagnostic criteria on USG (Rule of 3 and 4) are: * **Pyloric muscle thickness > 3 mm** (most reliable) * **Pyloric channel length > 14 mm** * **Pyloric diameter > 10 mm** Additionally, USG can show the "Target sign" or "Donut sign" in cross-section. **Why Other Options are Incorrect:** * **A. Barium Meal:** Previously the gold standard, it is now reserved for cases where USG is inconclusive. It shows classic signs like the **"String sign"** (narrowed pyloric canal), **"Beak sign,"** or **"Mushroom sign."** However, it involves radiation and risk of aspiration. * **C & D. CT and MRI:** These are expensive, unnecessary, and may require sedation. They offer no diagnostic advantage over USG for this condition. **High-Yield Clinical Pearls for NEET-PG:** * **Clinical Presentation:** Non-bilious, projectile vomiting in a 3–6 week old infant. * **Physical Exam:** A palpable, mobile, hard, **olive-shaped mass** in the epigastrium and visible gastric peristalsis. * **Metabolic Abnormality:** Hypochloremic, hypokalemic, metabolic alkalosis with **paradoxical aciduria**. * **Management:** Initial step is fluid resuscitation (Normal Saline); definitive treatment is **Ramstedt’s Pyloromyotomy**.

Q: A 5-year-old child presents with diarrhea. How much oral rehydration solution (ORS) should be administered according to Plan A after each episode of stool?

100 ml. **Explanation:** The management of diarrhea in children is categorized into three plans (A, B, and C) based on the degree of dehydration. This question pertains to **Plan A**, which is used for children with **no signs of dehydration** to prevent it from developing. **Why Option B is Correct:** According to the WHO and IAP guidelines for Plan A, the amount of ORS to be administered after each loose stool depends on the child's age: * **Children <2 years:** 50–100 ml after each stool. * **Children 2–10 years:** 100–200 ml after each stool. * **Older children/Adults:** As much as they want. Since the child in the question is **5 years old**, the appropriate dose falls within the **100–200 ml** range. Among the choices provided, **100 ml** is the standard minimum recommended volume for this age group. **Analysis of Incorrect Options:** * **Option A (50 ml):** This is the lower limit for infants and children under 2 years of age. * **Option C (200 ml):** While 200 ml is the upper limit for a 5-year-old, 100 ml is the standard benchmark often tested in exams for the start of the 2–10 year range. * **Option D (According to thirst):** While thirst is a guide for older children and adults, specific volume guidelines are mandated for younger children to ensure adequate replacement of losses. **High-Yield Clinical Pearls for NEET-PG:** * **Plan B (Some Dehydration):** Dose is **75 ml/kg** over 4 hours. * **Plan C (Severe Dehydration):** Requires IV fluids (Ringer’s Lactate). Dose is **100 mg/kg** (30 ml/kg then 70 ml/kg). * **Zinc Supplementation:** Essential in all diarrhea cases; **10 mg/day** for infants 6 months for 14 days. * **ORS Composition:** Low osmolarity ORS (245 mOsm/L) is the current standard.

Q: What is the total osmolarity of low osmolarity ORS?

245 mmol/litre. **Explanation:** The World Health Organization (WHO) and UNICEF recommended the **Low Osmolarity ORS** (Oral Rehydration Solution) in 2004 to replace the standard ORS. The correct osmolarity is **245 mmol/L**. **Why 245 mmol/L is correct:** The shift from the older formula (311 mmol/L) to the low osmolarity version (245 mmol/L) was driven by clinical evidence showing that lower sodium and glucose concentrations reduce stool output, decrease the incidence of vomiting, and minimize the need for unscheduled intravenous fluids. The reduced sodium (75 mmol/L) and glucose (75 mmol/L) maintain the 1:1 molar ratio required for optimal sodium-glucose co-transport in the small intestine while avoiding osmotic diarrhea. **Analysis of Incorrect Options:** * **A. 311 mmol/L:** This was the osmolarity of the **Standard (Old) WHO ORS**. It was discontinued due to the risk of hypernatremia and increased stool output in children with non-cholera diarrhea. * **B. 300 mmol/L:** This is a distractor value and does not correspond to any WHO-recommended ORS formulation. * **D. 250 mmol/L:** While close, it is technically incorrect. The precise sum of the components (Sodium 75 + Chloride 65 + Glucose 75 + Potassium 20 + Citrate 10) equals exactly 245 mmol/L. **High-Yield Clinical Pearls for NEET-PG:** * **Composition of Low Osmolarity ORS (mmol/L):** Sodium (75), Chloride (65), Glucose (75), Potassium (20), Trisodium Citrate (10). * **Total Weight:** 20.5 grams per liter. * **Re-Reduced ORS:** Used specifically in **SAM (Severe Acute Malnutrition)**, known as **ReSoMal**, which has an even lower osmolarity (approx. 300 mOsm/L but with only 45 mmol/L Sodium) and higher Potassium. * **Zinc Supplementation:** Always given alongside ORS (10 mg/day for infants 6 months) for 14 days to reduce the duration and recurrence of diarrhea.

Q: What is the primary benefit of Oral Rehydration Solution (ORS) plus Zinc?

Reduces the duration of diarrhea. **Explanation:** The correct answer is **C. Reduces the duration of diarrhea.** Zinc supplementation is a cornerstone in the management of acute diarrhea in children, as recommended by the WHO and UNICEF. The primary therapeutic benefit of Zinc is its ability to **reduce the duration and severity of the diarrheal episode**. Mechanistically, Zinc acts as an intestinal "astringent" and a vital cofactor for over 300 enzymes. It improves the absorption of water and electrolytes, regenerates the intestinal epithelium (brush border), and enhances the local immune response, thereby accelerating recovery. **Analysis of Incorrect Options:** * **A. Reduces the incidence of infections:** While Zinc does boost immunity and can reduce the incidence of *subsequent* episodes of diarrhea for 2–3 months, its primary role during an active episode (alongside ORS) is therapeutic (reducing duration) rather than prophylactic against all infections. * **B. Acts as an antispasmodic agent:** Zinc has no direct effect on smooth muscle relaxation or intestinal motility; it works at the cellular and enzymatic level of the mucosa. * **C. Enhances sodium absorption:** This is the primary function of **Glucose** in the ORS (via the SGLT-1 transporter), not Zinc. While Zinc helps restore the mucosal surface, it is not the primary driver of the sodium-glucose co-transport mechanism. **High-Yield Clinical Pearls for NEET-PG:** * **WHO Recommended Dosage:** 20 mg/day for children >6 months and 10 mg/day for infants <6 months, for a total of **14 days**. * **Impact:** Zinc reduces the stool volume and the likelihood of the episode persisting beyond 7 days (persistent diarrhea). * **ORS Composition:** Remember that the current standard is **Low Osmolarity ORS** (245 mOsm/L) to minimize the risk of osmotic diarrhea and the need for IV fluids.

Question 1

At what age does a baby with congenital hypertrophic pyloric stenosis typically show symptoms?

Accepted Answer

Between the 3rd and 4th week of life

Answer

At the time of birth

Answer

During the first week of life

Answer

During the second month of life

Question 2

What is the most common cause of colonic obstruction in neonates?

Accepted Answer

Aganglionic colon

Answer

Meconium ileus

Answer

Ileal atresia

Answer

Volvulus

Question 3

A 3-week-old boy presents with projectile, non-bilious vomiting after feeding. Physical examination reveals a firm, olive-like mass in the epigastric region. Ultrasound shows thickened pyloric muscle. What is the most likely pathological finding if the pyloric muscle is biopsied?

Accepted Answer

Hypertrophy of the muscularis propria

Answer

Inflammation of the mucosa

Answer

Dilatation of the stomach

Answer

Stricture of the duodenum

Question 4

An infant presented with failure to thrive, stridor, otitis media, and esophagitis. What is the most probable diagnosis?

Accepted Answer

Gastroesophageal reflux disease

Answer

Tracheoesophageal fistula

Answer

Hypertrophic pyloric stenosis

Answer

Duodenal atresia

Question 5

A newborn girl has not passed meconium for 48 hours, presents with abdominal distention and vomiting. What is the initial investigation of choice?

Accepted Answer

Lower GI contrast study

Answer

Manometry

Answer

Genotyping for cystic fibrosis

Answer

Serum trypsin immunoblot

Question 6

A young boy presents with massive hematemesis. He had a fever for 15 days a few days back, which was treated with some drugs. Clinical examination reveals moderate splenomegaly. No other history is positive. What is the probable diagnosis?

Accepted Answer

Esophageal varices

Answer

Drug-induced gastritis

Answer

Esophageal tear

Answer

Bleeding duodenal ulcer

Question 7

If you suspect a child to have Congenital Hypertrophic Pyloric Stenosis clinically, what is the next best investigation?

Accepted Answer

USG

Answer

Barium meal

Answer

CT

Answer

MRI

Question 8

A 5-year-old child presents with diarrhea. How much oral rehydration solution (ORS) should be administered according to Plan A after each episode of stool?

Accepted Answer

100 ml

Answer

50 ml

Answer

200 ml

Answer

Administer according to thirst

Question 9

What is the total osmolarity of low osmolarity ORS?

Accepted Answer

245 mmol/litre

Answer

311 mmol/litre

Answer

300 mmol/litre

Answer

250 mmol/litre

Question 10

What is the primary benefit of Oral Rehydration Solution (ORS) plus Zinc?

Accepted Answer

Reduces the duration of diarrhea

Answer

Reduces the incidence of infections

Answer

Acts as an antispasmodic agent

Answer

Enhances sodium absorption

Gastroenterology — MCQs

Gastroenterology — MCQs

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