A 65-year-old white female with a history of arthritis, congestive heart failure, and osteoporosis complains of odynophagia for two weeks. A barium swallow shows a moderate-sized crater just above the gastroesophageal junction. What is the least likely contributor to this condition?

Correct Answer: D

Rationale: The correct answer is D: Calcium channel blocker. Odynophagia is often associated with esophageal ulcers, which can be exacerbated by NSAIDs (A) due to their effect on the gastric mucosa. Alendronate (B) is a bisphosphonate used to treat osteoporosis and can cause esophagitis. Iron sulfate (C) can also irritate the esophagus. However, calcium channel blockers (D) are least likely to contribute to esophageal ulcers or odynophagia as they do not directly affect the esophagus or increase the risk of ulcers.

Correct Answer: B

Rationale: The correct answer is B: Irritable bowel syndrome (IBS). The key clues in the question are chronic constipation, bloating, abdominal pain relieved with defecation, and absence of alarming symptoms. These symptoms align with the Rome IV criteria for IBS. Inflammatory bowel disease (A) typically presents with more severe symptoms, including weight loss and blood in stools. Celiac disease (C) is associated with malabsorption symptoms and autoimmune features, not typically seen in this case. Lactose intolerance (D) presents with symptoms after consuming dairy, which is not mentioned in the patient's history. Therefore, based on the clinical presentation and exclusion of other conditions, the most likely diagnosis is IBS.

Correct Answer: C

Rationale: The correct answer is C: Acute pancreatitis. The patient's symptoms of severe epigastric pain radiating to the back, along with nausea, vomiting, and a history of heavy alcohol use, are classic for acute pancreatitis. Elevated serum amylase and lipase levels further support this diagnosis, as they are key markers of pancreatic inflammation. Acute cholecystitis (A) typically presents with right upper quadrant pain and fever. Peptic ulcer disease (B) is characterized by burning epigastric pain that improves with food intake. Gastroesophageal reflux disease (D) presents with heartburn and regurgitation, not the severe symptoms seen in this case.

Correct Answer: B

Rationale: The correct answer is B: Achalasia. The presentation of difficulty swallowing, weight loss, regurgitation of undigested food, and 'bird beak' appearance on barium swallow are classic for achalasia. In achalasia, there is impaired relaxation of the lower esophageal sphincter and absent peristalsis in the esophagus. This leads to functional obstruction and dilation of the esophagus, causing the characteristic 'bird beak' appearance. Incorrect Choices: A: Esophageal cancer typically presents with progressive dysphagia, weight loss, and may show a mass or stricture on imaging. C: Peptic stricture is usually seen in patients with long-standing gastroesophageal reflux disease or esophagitis. Symptoms are often related to acid reflux. D: Gastroesophageal reflux disease commonly presents with heartburn, regurgitation, and chest pain. It does not typically cause weight loss or the 'bird

Correct Answer: C

Rationale: The most likely diagnosis for the 28-year-old woman with abdominal pain, diarrhea, weight loss, mouth ulcers, and perianal fistula is Crohn's disease. Crohn's disease is characterized by inflammation that can occur anywhere in the digestive tract, leading to symptoms like abdominal pain, diarrhea, weight loss, mouth ulcers, and fistulas. Ulcerative colitis primarily affects the colon, not the entire digestive tract like in this case. Irritable bowel syndrome typically presents with abdominal pain and changes in bowel habits but not with fistulas. Diverticulitis is inflammation of pouches that can develop in the colon, but it does not typically present with mouth ulcers or fistulas.