A 25-year-old dental technician has noticed a 10-pound weight loss despite increased appetite, generalized weakness, and constipation with infrequent but unusually voluminous and malodorous stools. On physical examination, he is thin, pale, and appears tired. His abdomen is protuberant but soft. Labs reveal a microcytic anemia. Which of the following is least likely to be helpful?

Correct Answer: D

Rationale: The correct answer is D: Colonoscopy. In this scenario, the patient's symptoms point towards malabsorption, which is typically associated with issues in the small intestine, not the colon. Therefore, a colonoscopy, which examines the large intestine, would be least likely to be helpful in diagnosing the underlying cause of his symptoms. Choices A, B, and C would be more beneficial as they can help identify potential causes of malabsorption such as celiac disease, pancreatic insufficiency, or small bowel abnormalities.

Correct Answer: B

Rationale: The correct answer is B: Hepatocellular carcinoma. In this case, the patient with chronic hepatitis B has developed new-onset ascites, enlarged liver, and portal vein thrombosis, which are classic findings of hepatocellular carcinoma. The presence of ascites and portal vein thrombosis suggests advanced liver disease, increasing the likelihood of hepatocellular carcinoma. Acute flare of hepatitis (choice A) typically presents with elevated liver enzymes without the specific findings mentioned. Outflow obstruction and congestion (choice C) would not explain the portal vein thrombosis. Superinfection with hepatitis D (choice D) is unlikely as it typically occurs in patients with concurrent hepatitis B infection. Therefore, hepatocellular carcinoma is the most likely diagnosis in this patient based on the clinical presentation and imaging findings.

Correct Answer: A

Rationale: The correct answer is A: Bacterial infection by Helicobacter pylori. H. pylori is the most common cause of Peptic Ulcer Disease (PUD) as it infects the stomach lining, leading to inflammation and ulcer formation. Studies have shown a strong association between H. pylori infection and PUD. Other choices like high-fat diet and smoking can exacerbate PUD symptoms but are not the primary cause. Viral infections are not known to be a common cause of PUD. Therefore, A is the correct choice based on scientific evidence and research.

Correct Answer: B

Rationale: The correct answer is B. Sucralfate forms a protective barrier over ulcers by binding to the ulcer site and creating a physical barrier against acid and pepsin. This protects the ulcer from further damage and allows it to heal. The other choices are incorrect because: A: Sucralfate does not neutralize stomach acid, it works by forming a barrier. C: Sucralfate does not eradicate H. pylori, which is typically treated with antibiotics. D: Sucralfate does not inhibit acid production, it works by creating a protective barrier.

Correct Answer: D

Rationale: The correct answer is D: High intake of dairy products. PUD (Peptic Ulcer Disease) is commonly caused by factors like chronic NSAID use, H. pylori infection, and excessive alcohol consumption. High dairy intake does not directly contribute to PUD. Dairy products usually do not irritate the stomach lining or lead to ulcer formation. Thus, it is not a typical cause of PUD.