Gastroenterology — MCQs

A 25-year-old man presents with low-grade fever, weight loss, fatigue, crampy abdominal pain, episodic diarrhea, and postprandial bloating. Right lower quadrant tenderness is elicited on palpation of the abdomen. Capsule endoscopy reveals thickening of the terminal ileum, edema, marked luminal narrowing, and a cobblestone appearance of the mucosa. Which of the following is a characteristic of this condition?

Q317Medium

An elderly patient presents with a prolonged history of weakness and lethargy. On examination, the patient is found to be anemic and stool is positive for occult blood. Which of the following is the investigation of choice?

Q318Easy

Which of the following is NOT a precipitating factor for hepatic encephalopathy?

Q319Medium

Which statement is not true regarding erosive gastritis?

Q320Medium

What is the most specific antibody for celiac disease in patients with IgA deficiency?

Gastroenterology Indian Medical PG Practice Questions and MCQs

Question 311: A 50-year-old man became dizzy while passing stool and noticed fresh blood in the stool. Previous two concurrent colonoscopic examinations done for routine screening of carcinoma colon were normal. What is the most likely cause of the bleed?

A. Early carcinoma of the colon
B. Sigmoid diverticulitis
C. Microscopic colitis
D. Dilatation of veins of the colon (Correct Answer)

Explanation: **Explanation:** The clinical presentation of painless, brisk hematochezia (fresh blood in stool) in an older patient with a history of **normal colonoscopies** strongly points toward **Angiodysplasia** (dilatation of submucosal veins). [1] **1. Why "Dilatation of veins of the colon" is correct:** Angiodysplasia (vascular ectasia) consists of dilated, tortuous, thin-walled submucosal vessels. These lesions are often small, flat, and can be easily missed during colonoscopy, especially if the bowel prep is suboptimal or if the vessels are not actively bleeding at the time of the procedure. They are a common cause of lower GI bleeding in patients over 50 and typically present with episodic, painless bleeding. [1] **2. Why other options are incorrect:** * **Early carcinoma of the colon:** While a common cause of bleeding, it is unlikely here because the patient had *two* recent normal colonoscopies. Carcinomas are usually visible as intraluminal masses or ulcers. [2] * **Sigmoid diverticulitis:** This typically presents with "left-sided appendicitis" symptoms (fever, LLQ pain, and leukocytosis). While diverticulosis causes bleeding, diverticulitis (inflammation) rarely causes significant hematochezia. * **Microscopic colitis:** This condition presents with chronic, watery, non-bloody diarrhea. By definition, the colon looks endoscopically normal, but it does not cause brisk hematochezia. **Clinical Pearls for NEET-PG:** * **Most common site:** Angiodysplasia is most commonly found in the **cecum and ascending colon**. * **Association:** It is frequently associated with **Aortic Stenosis** (Heyde’s Syndrome) and Chronic Kidney Disease. * **Diagnosis:** If colonoscopy is negative and bleeding is brisk, **Angiography** (showing a tuft of vessels or early venous filling) is the next step. [1] * **Management:** Most cases stop spontaneously; persistent lesions are treated via colonoscopic thermal coagulation or argon plasma coagulation (APC).

Question 312: Autosomal Dominant Familial Nonhemolytic Hyperbilirubinemia occurs in all except?

A. Crigler-Najjar syndrome
B. Dubin-Johnson syndrome (Correct Answer)
C. Gilbe syndrome
D. Cryoglobulinemia

Explanation: **Explanation:** The question asks to identify which condition is **NOT** inherited in an **Autosomal Dominant (AD)** fashion among the listed familial nonhemolytic hyperbilirubinemias. **1. Why Dubin-Johnson Syndrome is the Correct Answer:** Dubin-Johnson syndrome is inherited in an **Autosomal Recessive (AR)** pattern. It is caused by a mutation in the **ABCC2 gene**, which encodes the multidrug resistance-associated protein 2 (MRP2). This defect leads to impaired biliary excretion of conjugated bilirubin [2]. A classic diagnostic feature is a **grossly black liver** due to the accumulation of epinephrine metabolites in lysosomes. **2. Analysis of Other Options:** * **Crigler-Najjar Syndrome (Type II):** Also known as Arias syndrome, this is inherited as **Autosomal Dominant**. It involves a partial deficiency of the UGT1A1 enzyme [1], resulting in unconjugated hyperbilirubinemia that responds to Phenobarbital. * **Gilbert Syndrome:** While the inheritance can be complex, it is frequently described in a clinical context as **Autosomal Dominant** with variable expressivity [3]. It results from a mutation in the promoter region of the UDP-glucuronyl transferase enzyme leading to reduced expression [3]. * **Cryoglobulinemia:** This is an outlier in the list as it is not a primary hyperbilirubinemia syndrome; however, in the context of this specific classic MCQ, it is often used as a distractor or associated with systemic conditions that do not follow the AR pattern of Dubin-Johnson. **High-Yield Clinical Pearls for NEET-PG:** * **Unconjugated Hyperbilirubinemia:** Gilbert (AD) and Crigler-Najjar (Type I: AR; Type II: AD) [1]. * **Conjugated Hyperbilirubinemia:** Dubin-Johnson (AR) and Rotor Syndrome (AR). * **Differentiating Feature:** In Dubin-Johnson, the liver is **black** and there is a reversal of the normal urinary coproporphyrin I to III ratio (80% is Coproporphyrin I). In Rotor syndrome, the liver is normal in appearance.

Question 313: Which one of the following causes intestinal pseudo-obstruction?

A. Hypothyroidism
B. Tricyclic antidepressant
C. Parkinsonism
D. All the above (Correct Answer)

Explanation: Intestinal pseudo-obstruction (Ogilvie’s syndrome when acute) is a clinical syndrome characterized by signs and symptoms of mechanical bowel obstruction (distension, pain, vomiting) without an actual physical lesion blocking the lumen. It results from **impaired gastrointestinal motility** due to disturbances in the enteric nervous system, smooth muscles, or autonomic nerve supply [1]. **Analysis of Options:** * **Hypothyroidism:** Low thyroid hormone levels lead to generalized slowing of metabolic processes, including decreased gut peristalsis [1]. Severe hypothyroidism (myxedema) is a classic metabolic cause of paralytic ileus and chronic pseudo-obstruction. * **Tricyclic Antidepressants (TCAs):** These drugs possess potent **anticholinergic properties**. By blocking acetylcholine (the primary neurotransmitter for gut contraction), they inhibit smooth muscle activity, leading to delayed transit and pseudo-obstruction. * **Parkinsonism:** This is a neurodegenerative disorder affecting the autonomic nervous system [1]. Both the disease pathology (degeneration of enteric neurons) and the medications used to treat it (e.g., anticholinergics, levodopa) contribute to severe colonic dysmotility. **High-Yield Clinical Pearls for NEET-PG:** * **Common Causes:** Electrolyte imbalances (Hypokalemia, Hypercalcemia), Diabetes Mellitus (autonomic neuropathy), Scleroderma (smooth muscle atrophy), and Narcotics/Opioids. * **Diagnosis:** Abdominal X-ray shows dilated bowel loops with air-fluid levels, but **CT scan** is essential to rule out mechanical obstruction (the

Question 314: Which of the following is not a feature of Crohn’s disease?

A. Continuous lesions (Correct Answer)
B. Non-caseating granulomas are present
C. Backwash ileitis may be associated with Crohn’s disease
D. Cobblestone appearance

Explanation: **Explanation:** The correct answer is **A. Continuous lesions**. This is a hallmark feature of **Ulcerative Colitis (UC)**, not Crohn’s Disease (CD). In Crohn’s disease, the inflammation is characterized by **"skip lesions,"** where areas of diseased bowel are separated by segments of healthy, normal mucosa [1]. **Analysis of Options:** * **A. Continuous lesions:** In UC, the disease starts in the rectum and extends proximally in a continuous, symmetrical fashion [1]. CD is patchy and asymmetrical. * **B. Non-caseating granulomas:** These are a pathognomonic histological feature of Crohn’s disease (found in about 40-60% of cases). Their presence helps differentiate CD from UC, as UC does not form granulomas. * **C. Backwash ileitis:** While primarily associated with UC (where inflammation from the colon "washes back" into the terminal ileum), it is a trick option. However, the question asks for a feature that is *not* characteristic of CD. Since CD primarily affects the terminal ileum (Ileocolic distribution), ileal involvement is a core feature, whereas "continuous lesions" is an absolute contraindication for a CD diagnosis [2]. * **D. Cobblestone appearance:** This occurs in CD due to deep longitudinal and transverse ulcers intersecting with islands of edematous, normal mucosa. **NEET-PG High-Yield Pearls:** * **Transmural Inflammation:** CD affects all layers of the bowel wall (leading to fistulas/strictures); UC is limited to the mucosa and submucosa [1]. * **Smoking:** Smoking is a risk factor for **Crohn’s** but is actually **protective** against Ulcerative Colitis. * **ASCA vs. p-ANCA:** CD is associated with **ASCA** (Anti-Saccharomyces cerevisiae antibodies), while UC is associated with **p-ANCA**. * **Creeping Fat:** The presence of mesenteric fat wrapping around the bowel is specific to Crohn’s disease.

Question 315: Which of the following is NOT a feature of Zollinger-Ellison syndrome?

A. Diarrhea non-responsive to fasting
B. Epigastric pain
C. Large gastric ulcer (Correct Answer)
D. Secretin study is the investigation of choice

Explanation: Explanation: Zollinger-Ellison Syndrome (ZES) is caused by a gastrin-secreting tumor (gastrinoma), leading to profound gastric acid hypersecretion [3]. Why "Large gastric ulcer" is the correct answer: In ZES, ulcers typically occur in the duodenum (over 75% of cases), often in atypical locations like the distal duodenum or jejunum. While ulcers in ZES are often multiple or refractory, they are predominantly duodenal, not gastric [1]. Gastric ulcers are less common because the gastric mucosa is relatively more resistant to the high acid levels compared to the small intestine. Analysis of incorrect options: * Diarrhea non-responsive to fasting: This is a classic feature. The massive acid load enters the small bowel, inactivating pancreatic enzymes and malabsorbing fat. Since the diarrhea is driven by hormonal (gastrin) hypersecretion rather than oral intake, it persists during fasting (secretory diarrhea). * Epigastric pain: This is the most common presenting symptom (75-90% of patients) due to peptic ulcer disease. * Secretin study: This is the investigation of choice (most sensitive and specific provocative test). In ZES, intravenous secretin paradoxically increases serum gastrin levels (>200 pg/mL), whereas it inhibits gastrin in normal individuals. Clinical Pearls for NEET-PG: * Location: Most gastrinomas are found in the "Gastrinoma Triangle" (confluence of cystic/common bile duct, junction of 2nd/3rd parts of duodenum, and neck/body of pancreas). * Association: 25% of cases are associated with MEN-1 syndrome (3Ps: Parathyroid, Pancreas, Pituitary) [2]. * Diagnosis: Initial screening is by Fasting Serum Gastrin (>1000 pg/mL is diagnostic). If borderline, perform the Secretin Stimulation Test. * Treatment: High-dose PPIs are the mainstay for symptom control; surgical resection is required for localized tumors.

Question 316: A 25-year-old man presents with low-grade fever, weight loss, fatigue, crampy abdominal pain, episodic diarrhea, and postprandial bloating. Right lower quadrant tenderness is elicited on palpation of the abdomen. Capsule endoscopy reveals thickening of the terminal ileum, edema, marked luminal narrowing, and a cobblestone appearance of the mucosa. Which of the following is a characteristic of this condition?

A. Additional typical findings include crypt abscesses and pseudopolyps.
B. Inflammation and ulceration limited to mucosa and submucosa with sparing of deeper layers.
C. It can affect any portion of the gastrointestinal tract, but the proximal jejunum is the most common site of involvement.
D. It can cause fistula formation between loops of affected bowel. (Correct Answer)

Explanation: ### Explanation The clinical presentation (young patient, weight loss, RLQ pain) and endoscopic findings (terminal ileum involvement, luminal narrowing, and **cobblestone appearance**) are classic for **Crohn’s Disease (CD)** [1]. **1. Why Option D is Correct:** Crohn’s Disease is characterized by **transmural inflammation**, meaning the inflammatory process extends through all layers of the bowel wall (mucosa to serosa). This leads to the formation of deep fissures and ulcers. When these ulcers penetrate through the serosa, they create tracts that connect the bowel lumen to other structures, resulting in **fistulas** (e.g., entero-enteric, entero-vesical, or perianal fistulas). **2. Why the Other Options are Incorrect:** * **Option A:** Crypt abscesses and pseudopolyps are hallmark features of **Ulcerative Colitis (UC)** [2]. While cryptitis can occur in CD, "pseudopolyps" are much more characteristic of the regenerative process in UC. * **Option B:** Inflammation limited to the mucosa and submucosa is the defining pathological feature of **Ulcerative Colitis** [2]. CD involves the entire thickness of the wall. * **Option C:** While CD can affect any part of the GI tract (mouth to anus), the **terminal ileum** is the most common site of involvement (ileocolic distribution), not the proximal jejunum [1]. **3. High-Yield Clinical Pearls for NEET-PG:** * **Pathology:** Look for **Non-caseating granulomas** (pathognomonic but only seen in ~30% of cases) and **"Skip lesions"** (discontinuous involvement). * **Radiology:** The **"String sign of Kantor"** on barium swallow indicates terminal ileal strictures [3]. * **Complications:** CD is associated with malabsorption (Vitamin B12 deficiency), gallstones (due to decreased bile acid reabsorption), and calcium oxalate kidney stones. * **Serology:** **ASCA** (Anti-Saccharomyces cerevisiae antibodies) is positive in CD, whereas **p-ANCA** is more common in UC.

Question 317: An elderly patient presents with a prolonged history of weakness and lethargy. On examination, the patient is found to be anemic and stool is positive for occult blood. Which of the following is the investigation of choice?

A. Colonoscopy (Correct Answer)
B. Barium meal
C. Barium enema
D. CT abdomen

Explanation: **Explanation:** The clinical presentation of an elderly patient with **iron deficiency anemia (IDA)** and **fecal occult blood (FOBT positive)** is highly suggestive of a gastrointestinal malignancy, most notably **Colorectal Cancer (CRC)**, until proven otherwise. **Why Colonoscopy is the Investigation of Choice:** Colonoscopy is the gold standard because it allows for direct visualization of the entire colonic mucosa from the rectum to the cecum. Its primary advantage over other modalities is the ability to perform **biopsies** of suspicious lesions and the **removal of polyps** (polypectomy) during the same procedure. In elderly patients with unexplained anemia, identifying right-sided colonic lesions (which often bleed occultly) is critical. **Analysis of Incorrect Options:** * **Barium Meal:** This evaluates the upper GI tract (esophagus, stomach, duodenum). While upper GI bleeds can cause anemia, the standard protocol for occult blood in an elderly patient mandates ruling out colonic pathology first or concurrently. * **Barium Enema:** This is an indirect imaging technique. It has lower sensitivity for small polyps or flat lesions and lacks the capability for tissue diagnosis (biopsy). It has largely been replaced by colonoscopy. * **CT Abdomen:** While useful for staging a known cancer or looking for extraluminal pathology, it is not sensitive enough to detect early mucosal lesions or small tumors compared to direct visualization. **NEET-PG High-Yield Pearls:** * **Rule of Thumb:** Any elderly patient with new-onset iron deficiency anemia has a GI malignancy until proven otherwise. * **Right-sided vs. Left-sided CRC:** Right-sided (ascending colon) tumors typically present with **occult blood and anemia**, whereas left-sided tumors present with **altered bowel habits and obstruction**. * **Next Step:** If colonoscopy is negative in a patient with IDA and occult blood, the next step is usually an **Upper GI Endoscopy (UGIE)** to rule out gastric causes.

Question 318: Which of the following is NOT a precipitating factor for hepatic encephalopathy?

A. High protein intake
B. Hematemesis
C. Infection
D. Diarrhea (Correct Answer)

Explanation: Hepatic Encephalopathy (HE) is a reversible neuropsychiatric syndrome caused by liver failure or portosystemic shunting, leading to the accumulation of neurotoxins (primarily ammonia) [1]. Precipitating factors are triggers that either increase ammonia production or decrease its clearance. **Why Diarrhea is the Correct Answer:** Diarrhea is generally **not** a precipitating factor. In fact, inducing diarrhea (osmotic laxation) using **Lactulose** is the standard treatment for HE. Lactulose works by acidifying the gut lumen, converting ammonia ($NH_3$) into non-absorbable ammonium ($NH_4^+$), and promoting its excretion through frequent bowel movements. **Analysis of Incorrect Options:** * **High Protein Intake:** Protein is broken down by gut bacteria into ammonia [1]. Excessive intake increases the nitrogenous load, overwhelming the liver's ability to detoxify it. * **Hematemesis (GI Bleed):** Upper GI bleeding is a major trigger. Blood in the gut acts as a massive "protein meal" (hemoglobin is protein-rich). Bacterial breakdown of this blood significantly spikes ammonia levels. * **Infection:** Sepsis or Spontaneous Bacterial Peritonitis (SBP) increases tissue catabolism and impairs renal function, both of which elevate blood ammonia levels. **NEET-PG High-Yield Pearls:** * **Most common precipitant:** Infections and GI bleeding. * **Metabolic triggers:** Hypokalemia and Metabolic Alkalosis (often caused by diuretics) are high-yield precipitants. Alkalosis shifts the equilibrium toward $NH_3$, which crosses the blood-brain barrier more easily. * **Constipation:** This is a classic precipitant (opposite of diarrhea) because it increases the transit time for bacterial ammonia production. * **Drug of choice:** Lactulose (first-line) and Rifaximin (add-on). **Clinical Grading:** The severity of HE is assessed using clinical signs ranging from poor concentration (Grade 1) to unconsciousness (Grade 4) [2].

Question 319: Which statement is not true regarding erosive gastritis?

A. Endoscopy is the investigation of choice.
B. Pain is absent.
C. It may be drug induced.
D. Barium meal may clinch the diagnosis. (Correct Answer)

Explanation: **Explanation:** Erosive gastritis (also known as hemorrhagic gastritis) is characterized by superficial mucosal lesions that do not penetrate the muscularis mucosa. **Why Option D is the correct (false) statement:** Barium meal is **not** useful for diagnosing erosive gastritis. Because the erosions are superficial and do not result in significant contour changes or deep craters, they are typically invisible on contrast radiography. Barium studies are better suited for detecting deep chronic ulcers or structural abnormalities like strictures. **Analysis of other options:** * **Option A:** **Upper GI Endoscopy (UGIE)** is the investigation of choice. It allows direct visualization of the gastric mucosa, showing multiple small, superficial erosions, petechiae, and friability. * **Option B:** Pain is often **absent** or minimal. Unlike peptic ulcer disease, erosive gastritis is frequently asymptomatic until it presents as painless hematemesis or melena. If symptoms occur, they are usually vague dyspepsia or epigastric discomfort. * **Option C:** It is commonly **drug-induced**, most notably by NSAIDs (which inhibit protective prostaglandins) and alcohol [1]. Other causes include severe physiological stress (Curling’s or Cushing’s ulcers) and portal hypertension [1]. **NEET-PG High-Yield Pearls:** * **Most common clinical presentation:** Upper GI bleeding (hematemesis/melena). * **Stress Gastritis:** Occurs in critically ill patients (burns, sepsis, trauma). Prophylaxis with PPIs or H2 blockers is standard in ICU settings [1]. * **NSAID Gastropathy:** The risk is systemic; even parenteral or rectal NSAIDs can cause erosions due to systemic COX-1 inhibition [1]. * **Management:** Removal of the offending agent (NSAIDs/Alcohol) and acid suppression with PPIs.

Question 320: What is the most specific antibody for celiac disease in patients with IgA deficiency?

A. Anti-endomysial antibodies
B. Anti-tissue transglutaminase antibodies
C. Anti-reticulin antibodies
D. Anti-gliadin antibodies (Correct Answer)

Explanation: ### Explanation **Concept Overview:** Celiac disease is strongly associated with **selective IgA deficiency** (occurring in 2–3% of patients). Standard screening tests, such as IgA anti-tissue transglutaminase (tTG) and IgA anti-endomysial antibodies (EMA), will yield **false-negative** results in these individuals because they cannot produce sufficient IgA [2]. In such cases, IgG-based versions of these tests must be used. **Why Option D is Correct:** While IgA-tTG is the overall best screening test for the general population, **Deamidated Gliadin Peptide (DGP) IgG antibodies** are highly sensitive and specific for diagnosing celiac disease in patients with IgA deficiency [1]. In the context of this specific question, "Anti-gliadin antibodies" (specifically the IgG subtype) remains the classic answer for this subset of patients. **Why Other Options are Incorrect:** * **A & B (Anti-endomysial and Anti-tTG):** These are typically measured as **IgA** antibodies. In a patient with IgA deficiency, these tests will be negative regardless of whether the disease is present. While IgG-tTG exists, it is generally considered slightly less specific than IgG-DGP in this specific clinical scenario. * **C (Anti-reticulin):** This is an older antibody test with low sensitivity and specificity; it is no longer used in modern clinical practice. **NEET-PG High-Yield Pearls:** * **Best Initial Screening Test:** IgA anti-tissue transglutaminase (tTG). * **Most Specific Test:** IgA anti-endomysial antibody (EMA). * **Gold Standard Diagnosis:** Small bowel biopsy showing villous atrophy, crypt hyperplasia, and increased intraepithelial lymphocytes (Marsh Classification) [1]. * **Mandatory Step:** Always check **Total Serum IgA levels** if celiac disease is suspected but serology is negative. * **HLA Association:** HLA-DQ2 (95%) and HLA-DQ8 [1].

Practice by Chapter

Esophageal Disorders

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Peptic Ulcer Disease

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Inflammatory Bowel Disease

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Irritable Bowel Syndrome

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Malabsorption Syndromes

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Pancreatitis (Acute and Chronic)

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Gastrointestinal Bleeding

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Liver Diseases and Cirrhosis

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Viral Hepatitis

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Biliary Tract Disorders

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Gastrointestinal Motility Disorders

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Gastrointestinal Malignancies

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