Gastroenterology — MCQs

A 50-year-old man presents to the emergency department with chief complaints of abdominal pain, distension, and bloody diarrhea for a day. Abdominal pain was episodic in nature and limited to the left lower quadrant. It was also associated with nausea and vomiting. He also has a history of postprandial abdominal pain for several months. He had an acute myocardial infarction which was treated with thrombolytics 3 months ago. He is a chronic smoker and has been diagnosed with diabetes mellitus for 10 years. On physical examination, the patient is ill-looking with a blood pressure of 90/60 mm Hg, pulse 100/min, respiratory rate of 22/min, temperature of 38.0°C (100.5°F) with oxygen saturation of 98% in room air. The abdomen is tender on palpation and distended. Rectal examination demonstrates bright red color stool. Leukocyte count is 14,000/mm3. Other biochemical tests were within normal ranges. Abdominal X-ray did not detect pneumoperitoneum or air-fluid level. The recent use of antibiotics was denied by the patient and stool culture was negative for C. difficile. Contrast-enhanced CT scan revealed segmental colitis involving the distal transverse colon. What is the most likely cause of the patient’s symptoms?

A 39-year-old woman comes to the physician because of recurrent episodes of severe pain over her neck, back, and shoulders for the past year. The pain worsens with exercise and lack of sleep. Use of over-the-counter analgesics have not resolved her symptoms. She also has stiffness of the shoulders and knees and tingling in her upper extremities that is worse in the morning. She takes escitalopram for generalized anxiety disorder. She also has tension headaches several times a month. Her maternal uncle has ankylosing spondylitis. Examination shows marked tenderness over the posterior neck, bilateral mid trapezius, and medial aspect of the left knee. Muscle strength is normal. Laboratory studies, including a complete blood count, erythrocyte sedimentation rate, and thyroid-stimulating hormone are within the reference ranges. X-rays of her cervical and lumbar spine show no abnormalities. Which of the following is the most likely diagnosis?

A 68-year-old man presents to his primary care physician for fatigue. He is accompanied by his granddaughter who is worried that the patient is depressed. She states that over the past 2 months he has lost 15 lbs. He has not come to some family events because he complains of being “too tired.” The patient states that he tries to keep up with things he likes to do like biking and bowling with his friends but just tires too easily. He does not feel like he has trouble sleeping. He does agree that he has lost weight due to a decreased appetite. The patient has coronary artery disease and osteoarthritis. He has not been to a doctor in “years” and takes no medications, except acetaminophen as needed. Physical examination is notable for hepatomegaly. Routine labs are obtained, as shown below: Leukocyte count: 11,000/mm^3 Hemoglobin: 9 g/dL Platelet count: 300,000/mm^3 Mean corpuscular volume (MCV): 75 µm^3 Serum iron: 35 mcg/dL An abdominal ultrasound reveals multiple, hypoechoic liver lesions. Computed tomography of the abdomen confirms multiple, centrally-located, hypoattenuated lesions. Which of the following is the next best step in management?

A 24-year-old woman presents with generalized edema, hematuria, and severe right-sided flank pain. Her vital signs are normal. A 24-hour urine collection shows >10 grams of protein in her urine. Serum LDH is markedly elevated. Contrast-enhanced spiral CT scan shows thrombosis of the right renal vein. Which of the following is the most likely mechanism behind this thrombosis?

An 81-year-old man is brought in by his neighbor with altered mental status. The patient's neighbor is unsure exactly how long he was alone, but estimates that it was at least 3 days. The neighbor says that the patient usually has his daughter at home to look after him but she had to go into the hospital recently. The patient is unable to provide any useful history. Past medical history is significant for long-standing hypercholesterolemia and hypertension, managed medically with rosuvastatin and hydrochlorothiazide, respectively. His vital signs include: blood pressure, 140/95 mm Hg; pulse, 106/min; temperature, 37.2°C (98.9°F); and respiratory rate, 19/min. On physical examination, the patient is confused and unable to respond to commands. His mucus membranes are dry and he has tenting of the skin. The remainder of the exam is unremarkable. Laboratory findings are significant for the following: Sodium 141 mEq/L Potassium 4.1 mEq/L Chloride 111 mEq/L Bicarbonate 21 mEq/L BUN 40 mg/dL Creatinine 1.4 mg/dL Glucose (fasting) 80 mg/dL Magnesium 1.9 mg/dL Calcium 9.3 mg/dL Phosphorous 3.6 mg/dL 24-hour urine collection Urine Sodium 169 mEq/24 hr (ref: 100–260 mEq/24 hr) Urine Creatinine 0.795 g/24 hr (ref: 1.0–1.6 g/24 hr) Which of the following is the most likely cause of this patient's acute renal failure?

A 67-year-old man presents to the emergency department with anxiety and trouble swallowing. He states that his symptoms have slowly been getting worse over the past year, and he now struggles to swallow liquids. He recently recovered from the flu. Review of systems is notable only for recent weight loss. The patient has a 33 pack-year smoking history and is a former alcoholic. Physical exam is notable for poor dental hygiene and foul breath. Which of the following is the most likely diagnosis?

A 58-year-old man comes to the clinic complaining of increased urinary frequency for the past 3 days. The patient reports that he has had to get up every few hours in the night to go to the bathroom, and says "whenever I feel the urge I have to go right away.” Past medical history is significant for a chlamydial infection in his twenties that was adequately treated. He endorses lower back pain and subjective warmth for the past 2 days. A rectal examination reveals a slightly enlarged prostate that is tender to palpation. What is the most likely explanation for this patient’s symptoms?

A 70-year-old man comes to the physician because of intermittent shortness of breath while going up stairs and walking his dog. It began about 1 month ago and seems to be getting worse. He has also developed a dry cough. He has not had any wheezing, fevers, chills, recent weight loss, or shortness of breath at rest. He has a history of Hodgkin lymphoma, for which he was treated with chemotherapy and radiation to the chest 7 years ago. He also has hypertension, for which he takes lisinopril. Ten years ago, he retired from work in the shipbuilding industry. He has smoked half a pack of cigarettes daily since the age of 21. Vital signs are within normal limits. On lung auscultation, there are mild bibasilar crackles. A plain x-ray of the chest shows bilateral ground-glass opacities at the lung bases and bilateral calcified pleural plaques. Which of the following is the greatest risk factor for this patient's current condition?

A 68-year-old woman comes to the physician because of increasing heartburn for the last few months. During this period, she has taken ranitidine several times a day without relief and has lost 10 kg (22 lbs). She has retrosternal pressure and burning with every meal. She has had heartburn for several years and took ranitidine as needed. She has hypertension. She has smoked one pack of cigarettes daily for the last 40 years and drinks one glass of wine occasionally. Other current medications include amlodipine and hydrochlorothiazide. She appears pale. Her height is 163 cm (5 ft 4 in), her weight is 75 kg (165 lbs), BMI is 27.5 kg/m2. Her temperature is 37.2°C (98.96°F), pulse is 78/min, and blood pressure is 135/80 mm Hg. Cardiovascular examination shows no abnormalities. Abdominal examination shows mild tenderness to palpation in the epigastric region. Bowel sounds are normal. The remainder of the examination shows no abnormalities. Laboratory studies show: Hemoglobin 10.2 g/dL Mean corpuscular volume 78 μm Mean corpuscular hemoglobin 23 pg/cell Leukocyte count 9,500/mm3 Platelet count 330,000/mm3 Serum Na+ 137 mEq/L K+ 3.8 mEq/L Cl- 100 mEq/L HCO3- 25 mEq/L Creatinine 1.2 mg/dL Lactate dehydrogenase 260 U/L Alanine aminotransferase 18 U/L Aspartate aminotransferase 15 U/L Lipase (N < 280 U/L) 40 U/L Troponin I (N < 0.1 ng/mL) 0.029 ng/mL An ECG shows normal sinus rhythm without ST-T changes. Which of the following is the most appropriate next step in the management of this patient?

A 27-year-old African American male presents to his family physician for “spots” on his foot. Yesterday, he noticed brown spots on his foot that have a whitish rim around them. The skin lesions are not painful, but he got particularly concerned when he found similar lesions on his penis that appear wet. He recalls having pain with urination for the last 4 weeks, but he did not seek medical attention until now. He also has joint pain in his right knee which started this week. He is sexually active with a new partner and uses condoms inconsistently. His physician prescribes a topical glucocorticoid to treat his lesions. Which of the following risk factors is most commonly implicated in the development of this condition?