Gastroenterology Practice Questions

Q: Which of the following statements about pseudomembranous colitis is false?

None of the above statements are false.. Pseudomembranous colitis is an inflammatory condition of the colon characterized by the presence of elevated yellow-white plaques (pseudomembranes) on the mucosal surface. 1. **Why Option D is correct:** All the provided statements (A, B, and C) are medically accurate descriptions of the disease's pathogenesis and management. Therefore, no statement is false. 2. **Analysis of Options:** * **Option A (True):** Antibiotic use is the primary risk factor. Broad-spectrum antibiotics (classically Clindamycin, Fluoroquinolones, and Cephalosporins) disrupt the normal colonic flora, allowing for the overgrowth of pathogenic bacteria [1]. * **Option B (True):** The causative agent is *Clostridioides difficile* (formerly *Clostridium*), a Gram-positive, spore-forming anaerobe [1]. It produces Toxin A (enterotoxin) and Toxin B (cytotoxin), which lead to mucosal inflammation and necrosis [1]. * **Option C (True):** Oral Vancomycin is a first-line treatment because it remains in the gut lumen and is not absorbed systemically, directly targeting the bacteria. Oral Fidaxomicin is another preferred first-line agent. **NEET-PG High-Yield Pearls:** * **Gold Standard Diagnosis:** Stool Cytotoxicity Assay (though rarely used now due to time). * **Most Sensitive Test:** GDH (Glutamate Dehydrogenase) screening. * **Most Specific/Practical Test:** Nucleic Acid Amplification Test (NAAT) for toxin genes. * **Endoscopy:** Shows characteristic "volcano lesions" or yellowish plaques. * **Treatment for Fulminant cases:** High-dose oral Vancomycin + IV Metronidazole. * **Recurrence:** Fecal Microbiota Transplant (FMT) is highly effective for multiple recurrences.

Q: What is the cause of pruritus in primary biliary cirrhosis?

Transient receptor potential vanilloid 1 (TRPV1). Pruritus is a common and distressing symptom of **Primary Biliary Cholangitis (PBC)**, formerly known as Primary Biliary Cirrhosis [1]. The pathophysiology involves the accumulation of cholestatic pruritogens (such as bile acids and lysophosphatidic acid) that activate specific neural pathways [2]. **Why TRPV1 is correct:** Recent research has identified **Transient Receptor Potential Vanilloid 1 (TRPV1)**, a non-selective cation channel found on sensory neurons, as a key mediator in cholestatic itch [2]. Pruritogens like **Lysophosphatidic Acid (LPA)**, formed by the enzyme autotaxin, activate these TRPV1 channels on peripheral nerve endings, leading to the transmission of the itch sensation to the central nervous system. **Analysis of Incorrect Options:** * **A. TLR4:** This is a pattern recognition receptor involved in innate immunity and the inflammatory response to LPS (endotoxin), not the primary mediator of pruritus. * **B. GLP-1:** This is an incretin hormone involved in glucose homeostasis and insulin secretion. * **D. GRP:** While Gastrin-releasing peptide is a known neurotransmitter in the spinal cord's "itch circuit," the specific peripheral trigger mechanism highlighted in recent PBC studies emphasizes the role of the TRPV1 channel. **High-Yield Clinical Pearls for NEET-PG:** * **First-line treatment for PBC pruritus:** Cholestyramine (bile acid sequestrant). * **Second-line/Alternative treatments:** Rifampicin (induces P450 to metabolize pruritogens), Naltrexone (opioid antagonist), and Sertraline (SSRI). * **Diagnostic Marker:** Anti-Mitochondrial Antibody (AMA) is positive in >95% of cases [3]. * **Key Enzyme:** **Autotaxin** levels correlate with the severity of cholestatic itch.

Q: What is the best diagnostic test for esophageal motility disorders?

Manometry. **Explanation:** **Esophageal Manometry** is the **gold standard** and best diagnostic test for evaluating esophageal motility disorders (e.g., Achalasia cardia, Diffuse Esophageal Spasm, Nutcracker esophagus) [1]. It directly measures the pressure, timing, and coordination of the Lower Esophageal Sphincter (LES) and the esophageal body during swallowing. High-resolution manometry (HRM) is the modern iteration, providing a "topographic map" (Chicago Classification) to precisely categorize these disorders [1]. **Analysis of Incorrect Options:** * **Barium studies:** While often the initial screening test (showing the "bird’s beak" appearance in Achalasia or "corkscrew" esophagus in DES), it is a structural/radiological study and cannot definitively quantify pressure or motor function [1]. * **Esophagoscopy:** Primarily used to rule out mechanical obstructions or "pseudoachalasia" (malignancy at the GE junction) [1]. It cannot diagnose motility issues as the esophagus often appears normal or merely dilated. * **24-hour pH monitoring:** This is the gold standard for diagnosing **Gastroesophageal Reflux Disease (GERD)**, not motility disorders. It measures acid exposure time but does not assess peristalsis. **High-Yield Clinical Pearls for NEET-PG:** * **Achalasia Cardia:** Characterized on manometry by **incomplete LES relaxation** (Integrated Relaxation Pressure >15 mmHg) and **aperistalsis** in the distal esophagus [1]. * **Nutcracker Esophagus:** Characterized by high-amplitude peristaltic contractions (>180 mmHg) [1]. * **Initial vs. Best:** For dysphagia, the initial test is often Barium Swallow or Endoscopy, but the **most definitive/best** test for motility is always Manometry [1].

Q: All of the following are true of duodenal ulcer pain except:

Relieved by alcohol. The correct answer is **D (Relieved by alcohol)**. Alcohol is a known gastric mucosal irritant that stimulates acid secretion [3] and delays mucosal healing; therefore, it typically **exacerbates** rather than relieves the pain of a duodenal ulcer (DU) [2]. **Analysis of Options:** * **A & B (Relieved by food / Occurs 2-3 hours after meals):** These are classic features of DU. In DU, pain occurs when the stomach is empty (the "hunger pain" cycle). Food or antacids buffer the acid, providing temporary relief. Pain typically returns 2–3 hours post-prandially when the acid load enters the duodenum [1]. * **C (Periodic pain):** DU pain is characteristically episodic or "periodic." Patients often experience symptomatic periods lasting several weeks followed by symptom-free intervals of weeks or months. **Clinical Pearls for NEET-PG:** 1. **Night Pain:** DU is the most common cause of nocturnal pain (occurring between 11 PM and 2 AM) because circadian acid secretion is highest at night. 2. **Food Relationship:** * **Duodenal Ulcer:** Food **relieves** pain (Weight gain may occur). * **Gastric Ulcer:** Food **aggravates** pain (Weight loss is common). 3. **Etiology:** *H. pylori* is the most common cause of DU (up to 90% of cases) [1]. 4. **Complications:** The most common complication of DU is **bleeding** (posterior wall), while the most common cause of **perforation** is an anterior wall ulcer [2].

Question 1

What is true about ulcerative colitis?

Accepted Answer

Involves the rectum and then extends proximally throughout the colon.

Answer

Involves only the colon.

Answer

Skip lesions are seen.

Answer

The ileum is not involved.

Question 2

A patient with compensated liver cirrhosis presented with a history of variceal bleed. What is the preferred mode of treatment in this patient?

Accepted Answer

Endoscopic sclerotherapy

Answer

Propranolol

Answer

Liver transplantation

Answer

TIPS

Question 3

Which of the following statements about pseudomembranous colitis is false?

Accepted Answer

None of the above statements are false.

Answer

It commonly occurs after antibiotic use.

Answer

It is primarily caused by Clostridium difficile.

Answer

Oral vancomycin is a standard treatment.

Question 4

In patients who have undergone appendicectomy, which of the following conditions is less likely to develop?

Accepted Answer

Ulcerative colitis

Answer

Crohn's disease

Answer

Both

Answer

None

Question 5

Which of the following findings is NOT typically seen in exudative ascites?

Accepted Answer

Serum-Ascites Albumin Gradient (SAAG) > 1.1 gm/dl

Answer

Protein > 2.5 gm/dl

Answer

Specific gravity > 1.016

Answer

None of the above

Question 6

What is the cause of pruritus in primary biliary cirrhosis?

Accepted Answer

Transient receptor potential vanilloid 1 (TRPV1)

Answer

Toll-like receptor 4 (TLR4)

Answer

Glucagon-like peptide 1 (GLP-1)

Answer

Gastrin-releasing peptide (GRP)

Question 7

What is the most common feature seen in patients with non-cirrhotic portal fibrosis?

Accepted Answer

Esophageal varices

Answer

Gastric varices

Answer

Ascites

Answer

Portal gastropathy

Question 8

What is the best diagnostic test for esophageal motility disorders?

Accepted Answer

Manometry

Answer

Barium studies

Answer

Esophagoscopy

Answer

24-hour pH monitoring

Question 9

All of the following are true of duodenal ulcer pain except:

Accepted Answer

Relieved by alcohol

Answer

Relieved by food

Answer

Occurs 2-3 hours after a meal

Answer

Periodic pain

Question 10

All are features of bile acid diarrhea, EXCEPT:

Accepted Answer

Reduced bile acid pool

Answer

Extensive ileal involvement is seen

Answer

Hepatic synthesis compensates fecal loss

Answer

Good response to cholestyramine

Gastroenterology — MCQs

Gastroenterology — MCQs

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