MCQs on Pathophysiology of Gastrointestinal Diseases, with Revision Notes (One-Liners)

(GPAT, NIPER, AIIMS Pharmacist, Railway Pharmacist, SSC, ESIC & State Pharmacist Exams)

1. Inflammatory Bowel Disease (IBD)

Easy-to-Remember Notes

• IBD is a chronic immune-mediated inflammatory disease of the intestine.

• The two major types are Crohn's disease and Ulcerative colitis (UC).

• Crohn's disease: Can affect mouth to anus.

• Ulcerative colitis: Limited to the colon and rectum.

• Crohn's disease has skip lesions.

• Ulcerative colitis has continuous lesions.

• Crohn's disease causes transmural inflammation.

• UC involves only the mucosa and submucosa.

• Fistulas and strictures are common in Crohn's disease.

• Toxic megacolon is a life-threatening complication of ulcerative colitis.

• TNF-α is the major inflammatory cytokine in Crohn's disease.

• Crohn's disease is mainly Th1/Th17 mediated.

• UC is relatively Th2-mediated.

• Long-standing ulcerative colitis increases the risk of colorectal carcinoma.

• Anti-TNF drugs include Infliximab and Adalimumab.

Memory Trick

Crohn = "Cracks through the wall."

• Transmural

• Fistula

• Skip lesions

UC = "Uniform Colon."

• Continuous lesions

• Colon only

• Cancer risk

2. Peptic Ulcer Disease

• Peptic ulcer develops due to an imbalance between aggressive and protective factors.

• The two major causes are H. pylori infection and NSAIDs.

• H. pylori produces urease, which converts urea into ammonia.

• Ammonia neutralizes gastric acid around the bacterium.

• NSAIDs inhibit COX, decreasing prostaglandin synthesis.

• Prostaglandins increase mucus, bicarbonate secretion, and mucosal blood flow.

• Histamine stimulates acid secretion through H₂ receptors.

• Gastrin stimulates acid secretion from parietal cells.

• Parietal cells secrete HCl and intrinsic factor.

• Chief cells secrete pepsinogen.

• Zollinger–Ellison syndrome is caused by a gastrinoma.

• Duodenal ulcers are usually associated with increased acid secretion.

• Gastric ulcers often result from reduced mucosal protection.

Memory Trick

"No PG → No Protection."

Jaundice

• Jaundice is a yellow discoloration due to bilirubin >2–3 mg/dL.

• Bilirubin is formed from hemoglobin breakdown.

• Unconjugated bilirubin is water-insoluble.

• Conjugated bilirubin is water-soluble.

• Bilirubin is conjugated by UDP-glucuronyl transferase.

• Hemolytic jaundice causes increased unconjugated bilirubin.

• Obstructive jaundice causes increased conjugated bilirubin.

• Obstructive jaundice produces dark urine.

• Obstructive jaundice produces pale (clay-colored) stools.

• Neonatal jaundice results from immature UDP-glucuronyl transferase.

• Bilirubin reaches the intestine and is converted into urobilinogen.

• Stercobilin gives stool its brown color.

Memory Trick

Unconjugated = Insoluble
Conjugated = Can be excreted

4. Hepatitis

• Hepatitis is inflammation of the liver.

• Hepatocyte injury is mainly immune-mediated, especially in HBV.

• ALT is more liver-specific than AST.

• Acute viral hepatitis markedly increases ALT.

• HCV has the highest risk of chronic infection.

• HAV and HEV usually do not become chronic.

• HBV and HCV can cause cirrhosis.

• Ballooning degeneration indicates hepatocyte injury.

• Councilman bodies are apoptotic hepatocytes.

• Chronic hepatitis may progress to fibrosis and cirrhosis.

Memory Trick

HCV = Chronic Virus
HAV = Acute Virus

5. Typhoid Fever

• Caused by Salmonella Typhi.

• Transmission is by the feco-oral route.

• The organism enters through contaminated food and water.

• Salmonella survives inside macrophages.

• It spreads through the bloodstream causing bacteremia.

• Peyer's patches in the terminal ileum are primarily affected.

• Necrosis of Peyer's patches causes intestinal perforation.

• Typhoid ulcers are longitudinal.

• Relative bradycardia (Faget sign) is a classical clinical finding.

• Chronic carriers harbor bacteria in the gallbladder.

Memory Trick

Typhi → Travels in macrophages

6. Alcoholic Fatty Liver Disease (AFLD)

• Alcohol is metabolized by alcohol dehydrogenase.

• Ethanol metabolism increases NADH.

• Excess NADH promotes triglyceride synthesis.

• Fat accumulates inside hepatocytes.

• Fatty liver is the earliest reversible stage.

• Continued alcohol intake causes alcoholic hepatitis.

• Mallory-Denk bodies are characteristic.

• AST is usually higher than ALT.

• The typical AST:ALT ratio is about 2:1.

• Chronic alcoholism eventually leads to cirrhosis.

7. Non-Alcoholic Fatty Liver Disease (NAFLD)

• NAFLD occurs without significant alcohol intake.

• It is the hepatic manifestation of metabolic syndrome.

• Obesity is the strongest risk factor.

• Insulin resistance is the major pathogenic mechanism.

• Free fatty acids accumulate inside hepatocytes.

• Oxidative stress causes inflammation.

• NASH (Non-Alcoholic Steatohepatitis) is the progressive form.

• NASH can progress to fibrosis, cirrhosis, and hepatocellular carcinoma.

• Weight reduction improves NAFLD.

• Diabetes mellitus significantly increases disease progression.

Memory Trick

NAFLD = "Metabolic Syndrome in the Liver."

Comparison Table

• Feature. Crohn's Disease, Ulcerative Colitis

• Site Mouth to anus Colon Only

• Lesions Skip Continuous

• Inflammation Transmural Mucosal

• Fistula Common Rare

• Cancer risk Moderate High

• Jaundice Bilirubin Urine Stool

• Hemolytic Unconjugated↑ Normal Dark

• Hepatocellular Mixed Dark Normal/Pale

• Obstructive Conjugated↑ Dark Pale

• Alcoholic Liver Disease NAFLD

• Alcohol intake present No alcohol

• AST > ALT (≈2:1) ALT often ≥ AST

• Mallory bodies Usually absent

• NADH excess Insulin resistance

Q1. Which cytokine plays the most important role in the pathogenesis of Crohn's disease?

A. IL-4
B. IL-5
C. TNF-α
D. IL-10

Answer: C. TNF-α

Explanation: TNF-α is the major pro-inflammatory cytokine responsible for chronic intestinal inflammation in Crohn's disease. Anti-TNF drugs (Infliximab and Adalimumab) are highly effective.

Q2. Which feature differentiates Crohn's disease from ulcerative colitis?

A. Continuous lesions
B. Rectal involvement
C. Transmural inflammation
D. Limited to mucosa

Answer: C. Transmural inflammation

Explanation: Crohn's disease affects all layers of the bowel wall (transmural), whereas ulcerative colitis primarily involves the mucosa and submucosa.

Q3. "Skip lesions" are characteristic of

A. Ulcerative colitis
B. Crohn's disease
C. Peptic ulcer
D. Diverticulitis

Answer: B. Crohn's disease

Explanation: Crohn's disease shows discontinuous inflamed segments separated by normal bowel.

Q4. Which complication is more common in Crohn's disease?

A. Toxic megacolon
B. Intestinal fistula
C. Rectal bleeding
D. Pseudopolyps

Answer: B. Intestinal fistula

Explanation: Transmural inflammation causes fistulas, strictures, and abscesses.

Q5. Ulcerative colitis increases the risk of

A. Gastric carcinoma
B. Colon carcinoma
C. Pancreatic carcinoma
D. Liver carcinoma

Answer: B. Colon carcinoma

Explanation: Long-standing ulcerative colitis significantly increases colorectal cancer risk.

Q6. Which immune response predominates in Crohn's disease?

A. Th2 response
B. Th1-mediated response
C. IgE-mediated response
D. Complement activation

Answer: B. Th1-mediated response

Explanation: Crohn's disease is mainly Th1/Th17 mediated, whereas ulcerative colitis has a Th2-like response.

Peptic Ulcer Disease

Q7. The most common cause of duodenal ulcer is

A. Alcohol
B. H. pylori infection
C. Viral infection
D. Candida infection

Answer: B. H. pylori infection

Explanation: Approximately 90–95% of duodenal ulcers are associated with Helicobacter pylori infection.

Q8. NSAIDs produce peptic ulcers mainly by

A. Increasing gastrin secretion
B. Increasing acid secretion
C. Inhibiting prostaglandin synthesis
D. Stimulating mucus production

Answer: C. Inhibiting prostaglandin synthesis

Explanation: NSAIDs inhibit COX enzymes, decreasing protective prostaglandins, mucus, bicarbonate secretion, and mucosal blood flow.

Q9. Which factor directly damages gastric mucosal cells?

A. Bicarbonate
B. Mucus
C. Hydrogen ions
D. Prostaglandins

Answer: C. Hydrogen ions

Explanation: Excess H⁺ ions diffuse into damaged mucosa, causing cellular injury.

Q10. Zollinger-Ellison syndrome causes peptic ulcers due to

A. Increased prostaglandins
B. Gastrinoma
C. Viral gastritis
D. Autoimmune gastritis

Answer: B. Gastrinoma

Explanation: Gastrin-secreting tumors produce excessive acid, leading to refractory ulcers.

Q11. Which organism survives gastric acid by producing urease?

A. Salmonella
B. Helicobacter pylori
C. E. coli
D. Clostridium difficile

Answer: B. Helicobacter pylori

Explanation: Urease converts urea into ammonia, neutralizing gastric acid.

Q12. Which is NOT a protective factor against peptic ulcers?

A. Mucus
B. Bicarbonate
C. Prostaglandins
D. Histamine

Answer: D. Histamine

Explanation: Histamine stimulates acid secretion through H₂ receptors.

Jaundice

Q13. Hemolytic jaundice is associated with increased

A. Conjugated bilirubin
B. Unconjugated bilirubin
C. Albumin
D. Urobilinogen absence

Answer: B. Unconjugated bilirubin

Explanation: Excess RBC destruction overwhelms hepatic conjugation capacity.

Q14. Obstructive jaundice produces

A. Dark urine
B. Increased fecal stercobilin
C. Pale stools
D. Increased unconjugated bilirubin only

Answer: C. Pale stools

Explanation: No bile reaches the intestine, so stercobilin is absent.

Q15. Which bilirubin is water-soluble?

A. Unconjugated bilirubin
B. Albumin-bound bilirubin
C. Conjugated bilirubin
D. Free bilirubin

Answer: C. Conjugated bilirubin

Explanation: Conjugation with glucuronic acid makes bilirubin water soluble.

Q16. Neonatal physiological jaundice occurs mainly due to

A. Increased conjugation
B. Increased UDP-glucuronyl transferase activity
C. Immature glucuronyl transferase
D. Bile duct obstruction

Answer: C. Immature glucuronyl transferase

Explanation: Neonates have reduced bilirubin conjugation.

Q17. Which enzyme conjugates bilirubin?

A. ALT
B. AST
C. UDP-glucuronyl transferase
D. ALP

Answer: C. UDP-glucuronyl transferase

Explanation: This enzyme converts unconjugated bilirubin into conjugated bilirubin.

Q18. Hepatitis B virus primarily damages hepatocytes through

A. Direct viral cytotoxicity
B. Immune-mediated cytotoxicity
C. Endotoxin release
D. Complement deficiency

Answer: B. Immune-mediated cytotoxicity

Explanation: Cytotoxic T cells destroy infected hepatocytes.

Q19. Which hepatitis virus has the highest risk of chronic infection?

A. HAV
B. HEV
C. HCV
D. HDV

Answer: C. HCV

Explanation: Approximately 70–85% of HCV infections become chronic.

Q20. Ballooning degeneration is characteristic of

A. Viral hepatitis
B. Gallstones
C. Appendicitis
D. Gastritis

Answer: A. Viral hepatitis

Explanation: Ballooning degeneration reflects hepatocyte injury.

Q21. Which liver enzyme is most elevated in acute viral hepatitis?

A. ALP
B. ALT
C. GGT
D. LDH

Answer: B. ALT

Explanation: ALT is more liver-specific than AST.

Q22. Councilman bodies represent

A. Fat accumulation
B. Apoptotic hepatocytes
C. Fibrosis
D. Calcification

Answer: B. Apoptotic hepatocytes

Explanation: Acidophilic (Councilman) bodies are apoptotic liver cells.

Q23. Typhoid fever is caused by

A. Salmonella Typhi
B. Shigella dysenteriae
C. Vibrio cholerae
D. E. coli

Answer: A. Salmonella Typhi

Explanation: Salmonella Typhi invades intestinal mucosa and reticuloendothelial tissues.

Q24. Typhoid ulcers are commonly located in

A. Stomach
B. Duodenum
C. Ileum
D. Colon

Answer: C. Ileum

Explanation: Peyer's patches of the terminal ileum are primarily affected.

Q25. Which immune cells primarily harbor Salmonella Typhi?

A. Neutrophils
B. Macrophages
C. Eosinophils
D. Platelets

Answer: B. Macrophages

Explanation: Salmonella survives and multiplies inside macrophages.

Q26. Intestinal perforation in typhoid occurs due to necrosis of

A. Brunner's glands
B. Peyer's patches
C. Gastric glands
D. Paneth cells

Answer: B. Peyer's patches

Explanation: Necrosis leads to intestinal perforation and hemorrhage.

Q27. Which phase of typhoid shows bacteremia?

A. Only intestinal phase
B. Early systemic phase
C. Recovery phase
D. Carrier phase

Answer: B. Early systemic phase

Explanation: Salmonella spreads through blood during the first week.

Alcoholic Fatty Liver Disease (AFLD)

Q28. Alcohol metabolism increases hepatic

A. NAD⁺
B. NADH
C. ATP consumption
D. Glycogen synthesis

Answer: B. NADH

Explanation: Excess NADH promotes triglyceride synthesis and fatty liver.

Q29. The first reversible stage of alcoholic liver disease is

A. Cirrhosis
B. Fatty liver
C. Hepatocellular carcinoma
D. Portal hypertension

Answer: B. Fatty liver

Explanation: Hepatic steatosis is reversible after alcohol cessation.

Q30. Which enzyme is characteristically higher in alcoholic hepatitis?

A. ALT > AST
B. AST > ALT
C. ALP > AST
D. GGT < ALT

Answer: B. AST > ALT

Explanation: AST is typically about twice the ALT level (AST:ALT ≈ 2:1) in alcoholic liver disease.

Q31. Mallory-Denk bodies are composed mainly of

A. DNA fragments
B. Keratin intermediate filaments
C. Glycogen
D. Lipoproteins

Answer: B. Keratin intermediate filaments

Explanation: Mallory bodies are eosinophilic cytoplasmic inclusions in damaged hepatocytes.

Q32. The strongest risk factor for NAFLD is

A. Smoking
B. Obesity and insulin resistance
C. Vitamin C deficiency
D. Hyperthyroidism

Answer: B. Obesity and insulin resistance

Explanation: Insulin resistance promotes increased hepatic fat accumulation.

Q33. Which condition represents the progressive form of NAFLD?

A. Fatty liver
B. NASH
C. Hepatic cyst
D. Liver abscess

Answer: B. NASH

Explanation: Nonalcoholic steatohepatitis (NASH) includes steatosis, inflammation, and hepatocyte injury, which may progress to fibrosis and cirrhosis.

Q34. Which mechanism contributes most to NAFLD?

A. Autoimmunity
B. Increased free fatty acid influx to the liver
C. Viral infection
D. Iron deficiency

Answer: B. Increased free fatty acid influx to the liver

Explanation: Excess adipose lipolysis and insulin resistance increase free fatty acid delivery to hepatocytes.

Q35. Which statement is TRUE regarding NAFLD?

A. It occurs only in alcoholics.
B. It is strongly associated with metabolic syndrome.
C. It is caused by hepatitis B virus.
D. It never progresses to cirrhosis.

Answer: B. It is strongly associated with metabolic syndrome.

Explanation: NAFLD is considered the hepatic manifestation of metabolic syndrome and may progress to cirrhosis and hepatocellular carcinoma.

Q36. Which pair is correctly matched?

A. Crohn's disease: Continuous lesions
B. Ulcerative colitis: Transmural inflammation
C. Crohn's disease: Fistula formation
D. Ulcerative colitis: Skip lesions

Answer: C. Crohn's disease: Fistula formation

Explanation: Transmural inflammation in Crohn's disease predisposes to fistulas.

Q37. Dark urine with pale stools is most suggestive of

A. Hemolytic jaundice
B. Hepatocellular jaundice
C. Obstructive jaundice
D. Neonatal jaundice

Answer: C. Obstructive jaundice

Explanation: Conjugated bilirubin is excreted in urine, while the absence of bile pigments in the intestine results in pale stools.

Q38. Which disease is primarily associated with a Th1-mediated immune response?

A. Ulcerative colitis
B. Crohn's disease
C. Peptic ulcer
D. Typhoid

Answer: B. Crohn's disease

Explanation: Crohn's disease is driven predominantly by Th1/Th17 immune responses.

Q39. Which pathological feature is common to both alcoholic hepatitis and NASH?

A. Caseating granulomas
B. Hepatic steatosis with inflammation
C. Peyer's patch necrosis
D. Increased unconjugated bilirubin

Answer: B. Hepatic steatosis with inflammation

Explanation: Both conditions feature fat accumulation and inflammatory injury; however, alcohol is absent in NASH.

Q40. A patient has recurrent peptic ulcers despite proton pump inhibitor therapy and markedly elevated serum gastrin levels. The most likely diagnosis is

A. H. pylori infection
B. NSAID-induced ulcer
C. Zollinger-Ellison syndrome
D. Stress ulcer

Answer: C. Zollinger-Ellison syndrome

Explanation: Gastrin-secreting tumors (gastrinomas) cause excessive gastric acid secretion, leading to multiple, recurrent, and treatment-resistant peptic ulcers. This is a classic high-yield GPAT and NIPER concept.

Rapid Revision One-Liners (Frequently asked)

1. Crohn's disease shows skip lesions and transmural inflammation.

2. Ulcerative colitis is confined to the colon and rectum.

3. TNF-α is the key cytokine in Crohn's disease.

4. H. pylori produces urease to survive in the stomach.

5. NSAIDs cause ulcers by inhibiting prostaglandin synthesis.

6. Parietal cells secrete hydrochloric acid and intrinsic factor.

7. Conjugated bilirubin is water-soluble; unconjugated bilirubin is water-insoluble.

8. Neonatal jaundice results from immature UDP-glucuronyl transferase.

9. ALT is more liver-specific than AST.

10. HCV has the highest risk of chronic hepatitis.

11. Councilman bodies are apoptotic hepatocytes.

12. Salmonella Typhi survives within macrophages.

13. Typhoid ulcers occur in Peyer's patches of the terminal ileum.

14. Alcohol metabolism increases the hepatic NADH: NAD⁺ ratio.

15. Fatty liver is the earliest reversible stage of alcoholic liver disease.

16. Mallory-Denk bodies are characteristic of alcoholic hepatitis.

17. An AST: ALT ratio of about 2:1 suggests alcoholic liver disease.

18. Insulin resistance is the central mechanism in NAFLD.

19. NASH is the inflammatory, progressive form of NAFLD.

20. Long-standing ulcerative colitis increases the risk of colorectal carcinoma.

Dr. Alok Singh