3rd Gastrointestinal USMLE

A 35-year-old White man has a long past his- tory of diarrhea, rectal bleeding, crampy abdominal pain, and the passage of mucus. He now presents with a worsening of his symptoms despite taking his medications. A barium enema is performed and is shown in Fig. Which of the following is the most likely diagnosis of this new complication?

A 45-year-old man with a long history of alcohol intake comes into the emergency room with upper gastrointestinal (UGI) bleeding. Urgent endoscopy reveals the following findings. Which of the following is the most likely diagnosis?

A 50-year-old woman undergoes screening colonoscopy at her primary care physician’s recommendation. She has no family history of colorectal cancer. A single lesion is removed during the procedure and sent for pathologic examination. Which of the following findings carries the greatest risk of malignancy?

A 45-year-old HIV-positive woman comes to her primary care physician complaining of a 2-day history of bloody diarrhea. She states that she has been feeling well until 2 days ago, when she developed abdominal pain. She denies fevers, chills, night sweats, nausea, or vomiting. She admits to feeling tired over the last couple of weeks and has had a 2.3-kg (5-lb) weight loss over the past 2 weeks. Her stool sample shows WBCs and RBCs. Her Gram stain is shown in the image. Her CD4+ cell count is 201/mm³. Which of the following is the most likely cause of this woman’s symptoms?

A 75-year-old woman with a history of diabetes and coronary heart failure presents to the emergency department because of increasing abdominal girth. In recent months she has been feeling increasingly fatigued, and although she has had decreased appetite, she has gained weight. Her heart rate is 100/min and blood pressure is 112/70 mm Hg. She has scleral icterus; the skin over her face, neck, and lower legs is slightly bronze in color; she has palmar erythema; and she has numerous ecchymoses over her body. Her abdominal examination is significant for ascites. Laboratory tests show: Aspartate transaminase: 102 U/L Alanine transaminase: 97 U/L Alkaline phosphatase: 300 U/L Total bilirubin: 1.9 mg/dL Albumin: 2.9 g/dL Prothrombin time: 22 sec Partial thromboplastin time: 42 sec An ultrasound of her abdomen shows a shrunken and nodular liver. A liver biopsy using Perls Prussian blue stain is shown in the image. Which of the following is the most likely complication of her disease?

A term boy with Apgar scores of 9 and 9 at 1 and 5 minutes has failed to pass meconium at 72 hours. He has had no episodes of emesis, and his abdomen is only mildly distended to palpation. The patient’s mother reports that her older son had the same problem at birth. A plain radiograph of the abdomen shows a small bowel obstruction with numerous air-filled loops of bowel. The patient is treated with a diatrizoate meglumine (Gastrografin) enema, with good results. Which of the following is the most likely mechanism for this infant’s acute intestinal problem?

A 75-year-old woman comes to the emergency department with complaints of nausea and nonbilious, nonbloody vomiting over the past 4 days. The patient reports that both the nausea and vomiting come in “waves”; that is, several hours will pass during which she feels well before the vomiting suddenly recurs. A detailed history reveals that the woman was told several months ago that she “has stones in her gall-bladder,” but she has been too frightened to undergo surgery. She has not had a bowel movement for 7 days. Her temperature is 38.4°C (101.1°F) and the abdomen is distended with high-pitched bowel sounds. Which of the following is the most appropriate initial test for a patient with suspected gallstone ileus?

A 62-year-old woman with a history of diabetes mellitus presents to the emergency department complaining of severe abdominal pain for the past 12 hours, first beginning as dull pain near the umbilicus but now localized to the right lower quadrant. She initially thought she was suffering from heartburn, but decided to come to the hospital because of the unrelenting pain. The patient reports that just prior to examination by the physician, she experienced a sudden decrease in intensity of pain, but she remains feeling very uncomfortable and must remain on the stretcher. On examination the patient appears in distress secondary to pain, tachycardic, slightly hypotensive, and febrile at 39°C (102°F). She has a diffusely tender abdomen with point tenderness over her right lower quadrant, accompanied by guarding and rebound. Laboratory values showed a leukocytosis of 20,000/mm³ with 95% polymorphonuclear lymphocytes. After confirming the diagnosis with imaging, which of the following is the most appropriate management?

A 47-year-old woman presents to the emergency department with an 8-day history of left lower quadrant pain and semi-formed stools. Starting this afternoon, she has noticed blood in her stool as well as dizziness when she gets up from sitting. She denies fever, nausea, vomiting, weight loss, and night sweats. Her temperature is 37°C (98.6°F), heart rate is 104/ min, blood pressure is 120/82 mm Hg supine and 103/63 mm Hg when she sits up, and respiratory rate is 18/min. Physical examination reveals no peritoneal signs and is remarkable only for fecal occult blood on rectal examination. Laboratory results reveal a WBC count of 13,000/mm³ and hematocrit of 29%. Results of an x-ray of the abdomen are shown in the image. What is the best next step in management?

A 66-year-old woman presents to her physician because of recurrent painless bleeding on defecation over the past month. She has regular, soft bowel movements and no history of constipation or diarrhea. A recent diagnosis of aortic stenosis was an incidental finding on echocardiogram. She takes calcium and vitamin D supplements daily. Her last colonoscopy (at age 60) was normal. Heart rate is 82/min, blood pressure is 133/72 mm Hg, respiratory rate is 12/min, and temperature is 36.6°C (97.8°F). Physical examination reveals her conjunctivae are pink and mucosa is moist. She has no abdominal tenderness or palpable masses and no hemorrhoids or fissures. Stool is hemoccult positive. Colonoscopy shows a spider-like lesion in the ascending colon. Which of the following is the most likely diagnosis?

A 61-year-old woman is brought to the emergency department drowsy and disoriented, able only to follow simple commands. On examination her abdomen is distended and nontender, her skin has a yellow hue, and there are multiple spider nevi on her chest. In her purse, the physician finds prescriptions for peginterferon and ribavirin. When asked to raise her hands, the physician notices a coarse tremor. Laboratory tests show: Blood urea nitrogen: 17 mg/dL Creatinine kinase: 1.1 mg/dL Aspartate aminotransferase: 89 U/L Alanine aminotransferase: 93 U/L Total bilirubin: 3.1 mg/dL Ammonia: 124 μg/dL Which of the following is the most likely diagnosis?

A 74-year-old man presents to the emergency department with abdominal pain. The pain is deep and aching and is localized to the left lower quadrant. The man reports multiple episodes of diarrhea over the preceding week. He also reports having multiple similar episodes of abdominal pain in the past. On physical examination he is febrile and has tenderness to palpation of the left lower quadrant. His WBC count is 23,000/mm³. Results of CT are shown in the image. Which of the following is the most likely diagnosis?

A 62-year-old woman presents to her physician with complaints of heartburn, fatigue, and intermittent upper abdominal pain. The pain is often worse after meals and especially with spicy foods. She reports no recent nausea, vomiting, weight loss, dysphagia, or bright-red blood per rectum. However, her stools are darker than normal. Her last colonoscopy 2 years ago was unremarkable. Stool guaiac test result is positive. An initial complete blood cell count reveals: Hemoglobin: 10.1 g/dL Hematocrit: 33.2% Mean corpuscular volume: 74.6/mm³ Mean corpuscular hemoglobin concentration: 25.8% WBC count: 9200/mm³ Platelet count: 176,000/mm³ Ferritin: 11 ng/mL The patient undergoes upper endoscopy, which reveals erosive gastritis. She is started on omeprazole, 40 mg twice a day and oral iron sulfate supplementation, 325 mg three times a day with meals. Six months into treatment, abdominal pain and heartburn are resolved, but the patient still has fatigue and is pale. Repeat laboratory tests show: Hemoglobin: 9.9 g/dL Hematocrit: 30.2% Mean corpuscular volume: 74.2/mm³ Mean corpuscular hemoglobin concentration: 25.1% WBC count: 9800/mm³ Platelet count: 198,000/mm³ Ferritin: 10 ng/mL Repeat upper endoscopy is negative for bleeding and erosive gastritis. Stool guaiac test result is negative. Which of the following is the next best step in management?

A 51-year-old man presents to the ED complaining of epigastric pain that radiates to his back. He states that he drinks six packs of beer daily. You suspect he has pancreatitis. His BP is 135/75 mm Hg, HR is 90 beats per minute, temperature is 100.1°F, and his RR is 17 breaths per minute. Laboratory results reveal WBC 13,000/μL, hematocrit 48%, platelets 110/μL, amylase 1150 U/L, lipase 1450 IU, lactate dehydrogenase (LDH) 150 U/L, sodium 135 mEq/L, potassium 3.5 mEq/L, chloride 105 mEq/L, bicarbonate 23 mEq/L, BUN 15 mg/dL, creatinine 1.1 mg/dL, and glucose 125 mg/dL. Which of the following laboratory values are most specific for pancreatitis?

A 51-year-old man describes 1 week of gradually worsening scrotal pain and dysuria. He is sexually active with his wife. His temperature is 100.1°F, HR 81 beats per minute, BP 140/75 mm Hg, and oxygen saturation is 99% on room air. On physical examination, his scrotal skin is warm and erythematous. A cremasteric reflex is present. The posterior left testicle is swollen and tender to touch. Color Doppler ultrasonography demonstrates increased testicular blood flow. Urinalysis is positive for leukocyte esterase. What is the most likely diagnosis?

A 40-year-old woman presents to the ED complaining of fever and 1 day of increasingly severe pain in her RUQ. She denies nausea or vomiting and has no history of fatty food intolerance. The patient returned from a trip to Mexico 6 months ago. About 2 weeks ago she experienced intermittent diarrhea with blood-streaked mucus. Her BP is 130/80 mm Hg, HR is 107 beats per minute, temperature is 102°F, and RR is 17 breaths per minute. Physical examination reveals decreased breath sounds over the right lung base. Abdominal examination shows tenderness to percussion over the RUQ and normal active bowel sounds. There is no Murphy sign. Her WBC is 20,500/μL. Chest radiograph reveals a small right-pleural effusion. Which of the following is the most likely diagnosis?

A 25-year-old G3P1011 presents to the ED with a 6-hour history of worsening lower abdominal pain, mostly in the RLQ. She also noticed some vaginal spotting this morning. She is nauseated, but did not vomit. Her last menstrual period was 2 months ago, but her cycles are irregular. She is sexually active and has a history of pelvic inflammatory disease. Her BP is 120/75 mm Hg, HR is 95 beats per minute, temperature is 99.2°F, and RR is 16 breaths per minute. Her abdomen is tender in the RLQ. Pelvic examination reveals right adnexal tenderness. Her WBC count is slightly elevated and her β-hCG is positive. After establishing IV access, which of the following is the most appropriate next step in management?

A 40-year-old Asian woman presents to the emergency department complaining of intermittent epigastric pain. The pain is severe, lasts for a few hours, and is sometimes accompanied by nausea and vomiting. Her bowel movements have been normal. Her temperature is 38.3°C (100.9°F), pulse is 100/min, blood pressure is 150/80 mm Hg, and respiratory rate is 22/min. Physical examination reveals moderate obesity and mildly icteric sclerae. Bowel sounds are normal, with an abrupt halt of inspiration upon palpation of the RUQ, and guarding is noted. Laboratory values reveal a WBC count of 13,000/mm³, total bilirubin of 3.3 mg/dL, and normal liver enzymes and alkaline phosphatase levels. Which of the following is the first diagnostic imaging study that should be performed?

A 57-year-old woman presents to the ED with a basin in her hand and actively vomiting. You insert an IV catheter, start IV fluids, and administer an antiemetic agent. The patient feels much better but also complains of severe crampy abdominal pain that comes in waves. You examine her abdomen and note that it is distended and that there is a small midline scar in the lower abdomen. Upon auscultation, you hear high-pitched noises that sound like “tinkles.” Palpation elicits pain in all four quadrants but no rebound tenderness. She is guaiac negative. Which of the following is the most common cause of this patient’s presentation?

You are working in the ED on a Sunday afternoon when four people present with acute-onset vomiting and crampy abdominal pain. They were all at the same picnic and ate most of the same foods. The vomiting began approximately 4 hours into the picnic. They deny having any diarrhea. You believe they may have “food poisoning” so you place IV lines, administer IV fluids, and observe. Over the next few hours, the patients begin to improve, the vomiting stops, and their abdominal pain resolves. Which of the following is the most likely cause of their presentation?

A 45-year-old white man is brought to the emergency department by ambulance. He is waving wildly, trying to hit the “flying bats” that are all around him. He is very agitated and smells strongly of alcohol. The ambulance crew said they found the patient bleeding from the mouth outside a bar. They could not find any laceration on his mouth or lips and believe that the bleeding is internal. The patient screams that he will not stand for this maltreatment any longer and tries to stand up, at which point he begins to vomit. Blood pours out of his mouth, and the patient says, “Here we go again.” The ambulance crew tells the physician that there was also a lot of vomit at the bar where he was found. The physician is able to subdue the patient to obtain his vital signs. His blood pressure is 118/78 mm Hg, pulse is 98/ min, respiratory rate is 22/min, and temperature is 37.2°C (98.9°F). The physician is unable to obtain a history on the patient or con- tact any relatives or friends. No signs of obvious trauma are observed. Which of the following is the best next step in diagnosis?

A 65-year-old man comes to the emergency department complaining of left lower abdominal pain that began the prior morning. He became concerned when he developed bloody diarrhea overnight. He has experienced similar pain, although to a lesser degree, over the past 2 months, especially after eating. The pain usually resolved within 1–2 hours, and he never had bloody diarrhea. His past medical history is significant for coronary artery disease and hypertension. He has smoked one pack of cigarettes per day for the past 30 years. On physical examination he is afebrile, heart rate is 90/min, and blood pressure is 135/85 mm Hg. He is visibly uncomfortable but in no apparent distress. His abdominal examination is significant for left lower quadrant tenderness but no guarding or rebound. Which of the following is the most likely diagnosis?

A 53-year-old man presents to the emergency department with severe epigastric abdominal pain. His temperature is 37.2C, blood pressure 110/70 mm Hg, pulse 110/min, and respirations 20/min. Examination of the heart and lungs is normal, and his abdomen is tender in the epigastric region. His white count is 15,000/mL and amylase is 450 U/L (25–125 U/L). Which of the following laboratory abnormalities is also most likely to be present?

A 25-year-old previously healthy man experiences fatigue and malaise. One week ago he had a “viral” type illness consisting of a sore throat, fever, and myalgias. He now appears jaundiced, but the rest of the physical examination is normal. His investigations reveal a total bilirubin of 4 mg/dL (0.1–1.0 mg/dL) and a direct bilirubin of 0.3 mg/dL (0.0–0.3 mg/dL). Which of the following is the most likely diagnosis?

A 63-year-old woman with cirrhosis caused by chronic hepatitis C is hospitalized because of confusion. She has guaiac-positive stools and a low-grade fever. She has received lorazepam for sleep disturbance. On physical examination, the patient is confused. She has no meningeal signs and no focal neurologic findings. There is hyperreflexia and a nonrhythmic flapping tremor of the wrists. Which of the following is the most likely explanation for this patient’s mental status change?