Gastroenterology — MCQs
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What is the recommended content of citrate in Oral Rehydration Solution (ORS) in millimoles?
A 14-year-old boy presents with chronic diarrhea. Duodenal biopsy shows villous atrophy, and anti-endomysial and IgA TTG antibodies are positive. What is the treatment of choice?
A 2-week-old infant presents with protracted vomiting and poor oral intake. Examination reveals signs of dehydration and ambiguous genitalia. Serum electrolytes show hyponatremia, hypochloremia, and normal bicarbonate. Which of the following is the most common cause of ambiguous genitalia in this context?
A 4-day-old baby boy has not defecated since coming home from the hospital, despite normal feeding and absence of excessive vomiting. Rectal examination reveals a normal anus, anal canal, and rectum. However, a large fecal mass is found in the colon, and a large release of flatus and feces follows the rectal examination. Which of the following conditions would be suspected?
Which of the following conditions can present as painless lower gastrointestinal bleeding in a child?
Which of the following is NOT true about trichobezoars?
What is true about pyloric stenosis?
A toddler presents with a few drops of blood per rectum. What is the most probable diagnosis?
What is the amount of trisodium citrate dihydrate in WHO ORS formulation?
A child presents with massive hematemesis and a history of NSAID intake and current medication. The child also has moderate splenomegaly. What is the most likely diagnosis?
Gastroenterology Indian Medical PG Practice Questions and MCQs
Question 31: What is the recommended content of citrate in Oral Rehydration Solution (ORS) in millimoles?
- A. 20
- B. 25
- C. 30
- D. None of the above (Correct Answer)
Explanation: The correct answer is **None of the above** because the standard concentration of citrate in the current WHO-recommended Low Osmolarity ORS is **10 mmol/L**. ### **Detailed Explanation** **1. Why the correct answer is "None of the above":** The WHO and UNICEF transitioned from the "Standard ORS" to the **Low Osmolarity ORS** in 2002 to reduce the need for unscheduled IV fluids and decrease stool output. In this formulation, the concentration of **Trisodium citrate dihydrate** is 2.9 g/L, which provides **10 mmol/L** of citrate. Since none of the options (20, 25, or 30) match this value, "None of the above" is the correct choice. **2. Analysis of Incorrect Options:** * **Option A (20):** This is the concentration of **Potassium** (20 mmol/L) in ORS, not citrate. * **Option B (25):** This is the concentration of **Bicarbonate** (25 mmol/L) used in the *older* WHO ORS formulation before citrate replaced it due to better stability in tropical climates. * **Option C (30):** This does not correspond to any specific electrolyte concentration in the current ORS formula. ### **High-Yield Facts for NEET-PG** To master ORS questions, remember the **WHO Low Osmolarity ORS Composition (Total Osmolarity: 245 mOsm/L):** | Component | mmol/L | Grams/Litre | | :--- | :--- | :--- | | **Sodium** | 75 | 2.6 (Sodium Chloride) | | **Chloride** | 65 | - | | **Glucose (Anhydrous)** | 75 | 13.5 | | **Potassium** | 20 | 1.5 (Potassium Chloride) | | **Citrate** | **10** | 2.9 (Trisodium citrate) | **Clinical Pearls:** * **Role of Citrate:** It is added to correct metabolic acidosis caused by diarrhea and increases the shelf-life of ORS packets. * **Glucose-Sodium Cotransport:** ORS works on the principle that glucose absorption in the small intestine remains intact during cholera/diarrhea, and it "drags" sodium and water along with it via the SGLT-1 transporter. * **ReSoMal:** For children with Severe Acute Malnutrition (SAM), a special ORS called ReSoMal is used, which has **lower sodium (45 mmol/L)** and **higher potassium (40 mmol/L)**.
Question 32: A 14-year-old boy presents with chronic diarrhea. Duodenal biopsy shows villous atrophy, and anti-endomysial and IgA TTG antibodies are positive. What is the treatment of choice?
- A. Gluten-free diet (Correct Answer)
- B. Antibiotics
- C. Loperamide
- D. 5-ASA
Explanation: ### Explanation **Correct Option: A. Gluten-free diet** The clinical presentation and diagnostic markers point definitively toward **Celiac Disease** (Gluten-sensitive enteropathy). The presence of **villous atrophy** on duodenal biopsy, combined with highly specific serological markers like **anti-tissue transglutaminase (IgA tTG)** and **anti-endomysial antibodies (EMA)**, confirms the diagnosis. The cornerstone of management is a lifelong, strict **gluten-free diet (GFD)**. Eliminating gluten (found in wheat, barley, and rye) allows the intestinal mucosa to heal, resolves symptoms, and prevents long-term complications like nutritional deficiencies and intestinal lymphoma. **Why other options are incorrect:** * **B. Antibiotics:** These are used for infectious diarrhea or Small Intestinal Bacterial Overgrowth (SIBO). While SIBO can mimic malabsorption, it would not cause positive celiac serology. * **C. Loperamide:** This is an anti-motility agent used for symptomatic relief in functional diarrhea. It is contraindicated in inflammatory or malabsorptive conditions like Celiac disease as it does not treat the underlying pathology. * **D. 5-ASA (Mesalamine):** This is the mainstay of treatment for Inflammatory Bowel Disease (IBD), specifically Ulcerative Colitis. IBD presents with different biopsy findings (e.g., crypt abscesses) and negative celiac serology. **High-Yield Clinical Pearls for NEET-PG:** * **Gold Standard Diagnosis:** Small intestinal biopsy showing Marsh criteria (villous atrophy, crypt hyperplasia, and increased intraepithelial lymphocytes). * **Best Screening Test:** IgA anti-tTG antibody (highest sensitivity). * **Most Specific Test:** Anti-endomysial antibody (EMA). * **Associated Genetics:** HLA-DQ2 (95%) and HLA-DQ8. * **Dermatological Association:** Dermatitis herpetiformis (intensely pruritic vesicles on extensor surfaces). * **Safe Grains:** Rice, Maize (Corn), Millets, and Sorghum.
Question 33: A 2-week-old infant presents with protracted vomiting and poor oral intake. Examination reveals signs of dehydration and ambiguous genitalia. Serum electrolytes show hyponatremia, hypochloremia, and normal bicarbonate. Which of the following is the most common cause of ambiguous genitalia in this context?
- A. 5-alpha-reductase deficiency
- B. 21-hydroxylase deficiency (Correct Answer)
- C. 11-hydroxylase deficiency
- D. Maternal ingestion of virilizing drugs during pregnancy
Explanation: **Explanation:** The clinical presentation of a neonate with **protracted vomiting, dehydration, and ambiguous genitalia** (virilization in a female) strongly suggests **Congenital Adrenal Hyperplasia (CAH)**. **1. Why 21-hydroxylase deficiency is correct:** This is the most common cause of CAH (>90% of cases). A deficiency in this enzyme impairs the conversion of progesterone to deoxycorticosterone (mineralocorticoid pathway) and 17-OH progesterone to 11-deoxycortisol (glucocorticoid pathway). * **Salt-wasting:** Lack of aldosterone leads to hyponatremia, hyperkalemia (though this patient has hypochloremia, the electrolyte shift is classic for salt-wasting), and dehydration. * **Virilization:** Shunting of precursors into the androgen pathway causes ambiguous genitalia in 46,XX females. **2. Why other options are incorrect:** * **11-hydroxylase deficiency:** While it causes virilization, it leads to the accumulation of 11-deoxycorticoserone (a weak mineralocorticoid), which typically causes **hypertension and hypokalemia**, rather than salt-wasting and dehydration. * **5-alpha-reductase deficiency:** This affects 46,XY males, causing undervirilization (female-appearing or ambiguous external genitalia). It does **not** cause electrolyte imbalances or vomiting. * **Maternal ingestion of drugs:** While this can cause virilization of a female fetus, it would not cause the systemic "salt-wasting crisis" (vomiting/dehydration) seen in this infant. **High-Yield Clinical Pearls for NEET-PG:** * **Gold Standard Diagnosis:** Elevated serum **17-hydroxyprogesterone (17-OHP)** levels. * **Classic Electrolyte Triad:** Hyponatremia, Hyperkalemia, and Metabolic Acidosis. * **Karyotype:** Most infants with CAH and ambiguous genitalia are **46,XX** (genotypic females). * **Management:** Immediate fluid resuscitation and replacement of glucocorticoids (Hydrocortisone) and mineralocorticoids (Fludrocortisone).
Question 34: A 4-day-old baby boy has not defecated since coming home from the hospital, despite normal feeding and absence of excessive vomiting. Rectal examination reveals a normal anus, anal canal, and rectum. However, a large fecal mass is found in the colon, and a large release of flatus and feces follows the rectal examination. Which of the following conditions would be suspected?
- A. Imperforate anus
- B. Anal agenesis
- C. Anorectal agenesis
- D. Colonic aganglionosis (Correct Answer)
Explanation: **Explanation:** The clinical presentation is classic for **Hirschsprung Disease (HD)**, also known as **Colonic Aganglionosis**. **1. Why Colonic Aganglionosis is Correct:** The underlying pathology is the failure of neural crest cells to migrate to the distal colon, resulting in an absence of Meissner and Auerbach plexuses. This leads to a functional obstruction because the aganglionic segment cannot relax. * **Delayed passage of meconium:** 90% of HD patients fail to pass meconium within the first 24–48 hours. * **Blast Sign (Squirt Sign):** The rectal examination (digital stimulation) temporarily bypasses the narrowed aganglionic segment, leading to a sudden, forceful release of flatus and liquid feces. This is a hallmark diagnostic clue. **2. Why Other Options are Incorrect:** * **A, B, and C (Anorectal Malformations):** Imperforate anus, anal agenesis, and anorectal agenesis are structural/anatomical defects. In these cases, a physical examination would reveal an absent or ectopic anal opening. In this scenario, the rectal examination was "normal," ruling out these anatomical obstructions. **3. NEET-PG High-Yield Pearls:** * **Gold Standard Diagnosis:** Rectal Suction Biopsy (shows absence of ganglion cells and increased acetylcholinesterase staining). * **Radiology:** Barium enema shows a "transition zone" (dilated proximal colon and narrowed distal segment). * **Associated Condition:** Strongly associated with **Down Syndrome** (Trisomy 21). * **Most Common Site:** Rectosigmoid region (Short-segment disease). * **Complication:** The most serious complication is Hirschsprung-associated enterocolitis (HAEC), which can be life-threatening.
Question 35: Which of the following conditions can present as painless lower gastrointestinal bleeding in a child?
- A. Meckel's diverticulum
- B. Rectal polyp (Correct Answer)
- C. Anal fissure
- D. Acute appendicitis
Explanation: **Explanation:** The clinical presentation of **painless lower gastrointestinal (GI) bleeding** in a child is a classic NEET-PG scenario. **1. Why Rectal Polyp is correct:** Juvenile polyps (inflammatory hamartomas) are the most common cause of painless rectal bleeding in children aged 2–10 years. They are typically solitary, located in the rectum or sigmoid colon, and present as **bright red blood per rectum (BRBPR)** coating the stool. The bleeding is painless because the polyp lacks sensory innervation and bleeds due to surface ulceration or auto-amputation. **2. Analysis of Incorrect Options:** * **Meckel’s Diverticulum:** While this is a major cause of painless lower GI bleeding, it typically presents as **massive, "brick-red" or currant-jelly stools** (due to ectopic gastric mucosa causing ileal ulceration). In MCQ exams, if both are present, "Rectal Polyp" is often the preferred answer for simple "painless streaks of blood," whereas Meckel’s is associated with more significant volume loss. * **Anal Fissure:** This is the most common cause of rectal bleeding in infants; however, it is characteristically **painful**, often associated with constipation and crying during defecation. * **Acute Appendicitis:** This typically presents with periumbilical pain migrating to the right iliac fossa, fever, and vomiting. It does not typically cause lower GI bleeding. **Clinical Pearls for NEET-PG:** * **Most common cause of painless BRBPR in a child:** Juvenile Polyp. * **Most common cause of massive painless GI bleed:** Meckel’s Diverticulum (Diagnosis: Technetium-99m pertechnetate scan). * **Most common cause of painful GI bleed:** Anal fissure. * **Juvenile Polyposis Syndrome:** Defined as >5 polyps; carries an increased risk of GI malignancy and requires surveillance.
Question 36: Which of the following is NOT true about trichobezoars?
- A. It is caused by Trichuris. (Correct Answer)
- B. It is a psychiatric manifestation.
- C. It involves balls of hair in the stomach.
- D. Pulling the hair and sucking of hair is usually seen.
Explanation: ### Explanation **1. Why Option A is the Correct Answer (The "False" Statement):** The term **Trichobezoar** is derived from the Greek word *thrix* (hair) and the Persian *padzahr* (antidote). It has no association with *Trichuris trichiura* (Whipworm). While both share the prefix "tricho-" (meaning hair-like), *Trichuris* is a nematode infection of the large intestine, whereas a trichobezoar is a physical mass of ingested hair found in the stomach. **2. Analysis of Other Options:** * **Option B & D:** Trichobezoars are indeed a **psychiatric manifestation**. They result from a combination of **Trichotillomania** (an impulse-control disorder characterized by the urge to pull out one's hair) and **Trichophagia** (the compulsive eating/sucking of that hair). * **Option C:** By definition, a trichobezoar is a **concretion of hair** that becomes trapped in the gastric mucosal folds. Because hair is resistant to digestive enzymes and peristalsis, it accumulates into a large, foul-smelling "hairball." **3. Clinical Pearls for NEET-PG:** * **Rapunzel Syndrome:** This is a rare, severe form of trichobezoar where the "tail" of the hair mass extends through the pylorus into the small intestine (duodenum/jejunum), potentially causing obstruction or perforation. * **Demographics:** Most commonly seen in adolescent females with underlying emotional stressors or psychiatric comorbidities. * **Diagnosis:** The gold standard for diagnosis is **Upper GI Endoscopy**. On CT scan, it appears as a well-defined intraluminal mass containing mottled gas bubbles (the "mottled gas" sign). * **Treatment:** Small bezoars may be removed endoscopically, but large trichobezoars usually require **Laparotomy** (gastrotomy) for removal. Psychiatric counseling is mandatory to prevent recurrence.
Question 37: What is true about pyloric stenosis?
- A. Hypokalemia (Correct Answer)
- B. Hyponatremia
- C. Metabolic acidosis
- D. Hypochloremia
Explanation: **Explanation:** Infantile Hypertrophic Pyloric Stenosis (IHPS) typically presents with non-bilious, projectile vomiting. The hallmark metabolic derangement is **Hypochloremic, Hypokalemic, Metabolic Alkalosis with Paradoxical Aciduria.** **Why Hypokalemia is the correct focus:** While hypochloremia is the initiating event, **Hypokalemia** is a critical component of the metabolic profile. It occurs due to two main reasons: 1. **Direct Loss:** Loss of potassium in the vomitus. 2. **Renal Compensation:** As the body becomes dehydrated, aldosterone is secreted to retain sodium. To conserve sodium in the distal tubule, the kidney must excrete either Hydrogen (H+) or Potassium (K+). Initially, H+ is excreted (leading to paradoxical aciduria), but as the body becomes severely potassium-depleted, K+ is further lost in an attempt to maintain sodium levels. **Analysis of Incorrect Options:** * **B. Hyponatremia:** While mild sodium loss occurs, the most characteristic and "high-yield" electrolyte abnormalities are related to Chloride and Potassium. * **C. Metabolic Acidosis:** This is incorrect. Persistent vomiting of gastric HCl leads to a loss of hydrogen ions, resulting in **Metabolic Alkalosis**. * **D. Hypochloremia:** While hypochloremia is a classic finding in pyloric stenosis, in the context of many NEET-PG style questions where multiple options seem "correct," **Hypokalemia** is often emphasized as the dangerous late-stage complication that must be corrected before surgery. *(Note: If this were a "Multiple Correct" format, both A and D would be true; however, in single-best-answer formats, focus on the alkalosis-potassium axis).* **High-Yield Clinical Pearls for NEET-PG:** * **Classic Presentation:** 3–6 week old male, projectile non-bilious vomiting, "Olive-shaped" mass on palpation. * **Diagnosis:** Ultrasound is the investigation of choice (Pyloric muscle thickness >4mm, length >14mm). * **Paradoxical Aciduria:** Despite systemic alkalosis, the urine is acidic because the kidney prioritizes sodium retention over H+ excretion. * **Management:** It is a **medical emergency, not a surgical one.** Correct electrolytes first. The surgery of choice is **Ramstedt’s Pyloromyotomy.**
Question 38: A toddler presents with a few drops of blood per rectum. What is the most probable diagnosis?
- A. Rectal ulcer
- B. Adenomatous polyposis coli
- C. Juvenile rectal polyp (Correct Answer)
- D. Hemorrhoids
Explanation: **Explanation:** The most probable diagnosis for a toddler presenting with painless, bright red blood per rectum (hematochezia) is a **Juvenile Rectal Polyp**. These are hamartomatous (non-neoplastic) lesions and represent the most common type of gastrointestinal polyp in the pediatric age group, typically peaking between **2 and 5 years of age**. They are usually solitary, located in the rectosigmoid region, and often present as "a few drops of blood" at the end of defecation or on the surface of the stool. **Analysis of Incorrect Options:** * **Rectal Ulcer:** Solitary rectal ulcer syndrome is rare in toddlers and usually presents with straining, mucus discharge, and a history of chronic constipation or manual disimpaction. * **Adenomatous Polyposis Coli (FAP):** This is a premalignant condition characterized by hundreds of adenomatous polyps. It rarely presents with bleeding in early childhood; symptoms typically manifest in late adolescence or early adulthood. * **Hemorrhoids:** These are extremely rare in the pediatric population unless there is an underlying pathology causing portal hypertension (e.g., cirrhosis). **Clinical Pearls for NEET-PG:** * **Nature:** Juvenile polyps are **hamartomas**, not premalignant. * **Classic Presentation:** Painless hematochezia in a healthy child. * **Auto-amputation:** Occasionally, the stalk twists, leading to infarction and "auto-amputation," where the polyp is passed spontaneously in the stool. * **Diagnosis:** Digital Rectal Examination (DRE) can often palpate low-lying polyps; however, **colonoscopy** is the gold standard for diagnosis and therapeutic snare polypectomy. * **Differential:** If the bleeding were associated with severe abdominal pain and a "sausage-shaped mass," consider **Intussusception**.
Question 39: What is the amount of trisodium citrate dihydrate in WHO ORS formulation?
- A. 1.5 gm
- B. 2.5 gm
- C. 2.9 gm (Correct Answer)
- D. 3.9 gm
Explanation: **Explanation:** The current **WHO Reduced Osmolarity ORS** is the standard treatment for dehydration due to diarrhea. The correct amount of **Trisodium citrate dihydrate** in one liter of this formulation is **2.9 grams**. **Why 2.9 gm is correct:** Trisodium citrate was introduced to replace Sodium bicarbonate (used in older formulations) because it increases the shelf-life of the ORS packets in tropical climates. Functionally, citrate acts as an alkalinizing agent that corrects metabolic acidosis resulting from diarrhea. Furthermore, it enhances the intestinal absorption of sodium and water. **Analysis of Incorrect Options:** * **1.5 gm (Option A):** This is the amount of **Potassium Chloride** in the WHO ORS formulation. * **2.6 gm (Option B):** This is the amount of **Sodium Chloride** (common salt) in the formulation. (Note: In the older "Standard" ORS, this was 3.5 gm). * **3.9 gm (Option D):** This value does not correspond to any constituent of the standard ORS formulation. **High-Yield Clinical Pearls for NEET-PG:** * **Total Osmolarity:** The reduced osmolarity ORS has a total osmolarity of **245 mOsm/L** (compared to 311 mOsm/L in the older version). This reduction helps decrease stool output and prevents hypernatremia. * **Glucose Concentration:** It contains **13.5 gm** of anhydrous glucose. The glucose-sodium co-transport mechanism remains intact even during viral or bacterial diarrhea. * **Composition Summary (per Liter):** * NaCl: 2.6 g * KCl: 1.5 g * Trisodium citrate: 2.9 g * Glucose: 13.5 g * **Electrolyte Concentrations:** Na+ (75 mmol/L), K+ (20 mmol/L), Cl- (65 mmol/L), Citrate (10 mmol/L), and Glucose (75 mmol/L).
Question 40: A child presents with massive hematemesis and a history of NSAID intake and current medication. The child also has moderate splenomegaly. What is the most likely diagnosis?
- A. Esophageal varices (Correct Answer)
- B. Duodenal ulcer
- C. Drug-induced gastritis
- D. Peptic ulcer
Explanation: **Explanation:** The key to solving this clinical scenario lies in the physical finding of **moderate splenomegaly** in the presence of massive hematemesis. **1. Why Esophageal Varices is correct:** Massive hematemesis in a child with splenomegaly strongly suggests **Portal Hypertension**. In the pediatric age group, the most common cause of portal hypertension is **Extrahepatic Portal Venous Obstruction (EHPVO)**. Splenomegaly indicates back-pressure in the portal system, leading to the formation of esophageal varices. When these varices rupture, they cause painless, profuse (massive) hematemesis. While the history mentions NSAIDs, the presence of an enlarged spleen is the "pathognomonic" clue that shifts the diagnosis from simple mucosal injury to a vascular/portal issue. **2. Why other options are incorrect:** * **Drug-induced Gastritis & Peptic/Duodenal Ulcers:** While NSAIDs are a known cause of gastritis and ulcers (which can cause hematemesis), these conditions **do not cause splenomegaly**. The bleeding from gastritis is usually "coffee-ground" or less voluminous compared to the catastrophic bleed seen in variceal rupture. **3. NEET-PG High-Yield Pearls:** * **Most common cause of massive hematemesis in children:** Extrahepatic Portal Venous Obstruction (EHPVO). * **EHPVO Presentation:** Often presents as "well-child" with sudden hematemesis and isolated splenomegaly (normal liver functions). * **Management:** The immediate drug of choice for active variceal bleed is **Octreotide** (somatostatin analogue). Definitive management for EHPVO is often a surgical shunt (e.g., Rex shunt). * **Rule of thumb:** Hematemesis + Splenomegaly = Portal Hypertension/Varices until proven otherwise.
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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