GIT-10

A 36-year-old man is brought to the emergency department because of right upper abdominal pain and anorexia that began 3 days ago. The pain is nonradiating and has no alleviating or exacerbating factors. He does not have nausea or vomiting. He emigrated from Mexico 6 months ago and currently works at a pet shop. He has been healthy except for 1 week of bloody diarrhea 5 months ago. He is 182 cm (5 ft 11 in) tall and weighs 120 kg (264 lb); BMI is 36 kg/m2. His temperature is 38.8°C (101.8°F), pulse is 85/min, respirations are 14/min, and blood pressure is 120/75 mm Hg. Lungs are clear to auscultation. He has tenderness to palpation in the right upper quadrant. Laboratory studies show: Hemoglobin11.7 g/dLLeukocyte count14,000/mm3Segmented neutrophils74%Eosinophils2%Lymphocytes17%Monocytes7%Platelet count140,000/mm3SerumNa+139 mEq/LCl-101 mEq/LK+4.4 mEq/LHCO3-25 mEq/LUrea nitrogen8 mg/dLCreatinine1.6 mg/dLTotal bilirubin0.4 mg/dLAST76 U/LALT80 U/LAlkaline phosphatase123 U/L Ultrasonography of the abdomen shows a 4-cm round, hypoechoic lesion in the right lobe of the liver with low-level internal echoes. Which of the following is the most likely diagnosis?

Amebiasis

A 30-year-old woman, gravida 1, para 0, at 30 weeks' gestation is brought to the emergency department because of progressive upper abdominal pain for the past hour. The patient vomited once on her way to the hospital. She states that she initially had dull stomach pain about 6 hours ago, but now the pain is located in the upper abdomen and is more severe. There is no personal or family history of serious illness. She is sexually active with her husband. She does not smoke or drink alcohol. Medications include folic acid and a multivitamin. Her temperature is 38.5°C (101.3°F), pulse is 100/min, and blood pressure is 130/80 mm Hg. Physical examination shows right upper quadrant tenderness. The remainder of the examination shows no abnormalities. Laboratory studies show: Hemoglobin13.1 g/dLLeukocyte count17,000/mm3SerumUrea nitrogen20 mg/dLCreatinine0.8 mg/dLAlkaline phosphatase79 U/LBilirubinTotal1 mg/dLDirect0.3 mg/dL Urinalysis shows mild pyuria. Which of the following is the most likely diagnosis in this patient?

Appendicitis

A 47-year-old man comes to the emergency department because of a 12-hour history of nausea, loss of appetite, and abdominal pain. He has dyslipidemia and hypertension. Medications are atorvastatin and valsartan. His temperature is 38.2°C (100.8°F), pulse is 102/min, and blood pressure is 130/78 mm Hg. Lungs are clear to auscultation. Heart sounds are normal. On abdominal examination, there is periumbilical tenderness with mild guarding but no rebound tenderness. Bowel sounds are decreased. Laboratory studies show: Hemoglobin14 g/dLLeukocyte count12,000/mm3Segmented neutrophils76%Bands6%Eosinophils1.5%Basophils0.5%Lymphocytes13%Monocytes3%Platelet count310,000/mm3SerumUrea nitrogen11 mg/dLCreatinine0.9 mg/dLGlucose103 mg/dLLipase78 U/L (N = 14-280 U/L) ECG shows no abnormalities. Intravenous fluid resuscitation and antibiotic therapy are begun. Which of the following is the most appropriate next step in management?

CT scan of the abdomen with contrast

A 55-year-old woman comes to the emergency department because of a 24-hour history of severe lower abdominal pain. She has had two episodes of nonbloody vomiting today and has been unable to keep down food or fluids. She has not had a bowel movement since yesterday. She has hypertension, hyperlipidemia, and osteoarthritis. She had a cholecystectomy 5 years ago. She has smoked one pack of cigarettes daily for the last 20 years. Current medications include chlorthalidone, atorvastatin, and naproxen. Her temperature is 38.8°C (101.8°F), pulse is 102/min, respirations are 20/min, and blood pressure is 118/78 mm Hg. She is 168 cm (5 ft 6 in) tall and weighs 94 kg (207 lbs); BMI is 33 kg/m2. Abdominal examination shows a soft abdomen with hypoactive bowel sounds. There is moderate left lower quadrant tenderness. A tender mass is palpated on digital rectal examination. There is no guarding or rebound tenderness. Laboratory studies show: Hemoglobin13.3 g/dLHematocrit40%Leukocyte count17,000/mm3Platelet count188,000/mm3SerumNa+138 mEq/LK+4.1 mEq/LCl-101 mEq/LHCO3-22 mEq/LUrea nitrogen18.1 mg/dLCreatinine0.9 mg/dL Which of the following is most likely to confirm the diagnosis?

CT scan of the abdomen with contrast

A 70-year-old man comes to the physician because of episodes of watery stools for the past 6 weeks. During this period, he has also had recurrent episodes of reddening of the face, neck, and chest that last up to 30 minutes, especially following alcohol consumption. He has hypertension. Current medications include enalapril. He smoked one pack of cigarettes daily for 20 years but quit 8 years ago. He drinks two glasses of wine daily. He appears pale. He is 185 cm (6 ft 1 in) tall and weighs 67 kg (147.7 lb); BMI is 20 kg/m2. His temperature is 36.7°C (98°F), pulse is 85/min, and blood pressure is 130/85 mm Hg. Scattered expiratory wheezing is heard throughout both lung fields. Cardiac examination shows no abnormalities. The abdomen is soft and mildly tender. The remainder of the physical examination shows no abnormalities. A complete blood count and serum concentrations of urea nitrogen and creatinine are within the reference range. Which of the following is the most likely diagnosis in this patient?

Carcinoid syndrome

A 40-year-old woman comes to the physician for right lower abdominal pain for the past 6 months. She has multiple nonbloody, watery bowel movements daily and experiences abdominal cramping. Sometimes, she feels sudden palpitations and shortness of breath, and her face becomes red. She has lost 7 kg (15 lb) over the past 3 months. She went on a 3-week hiking trip to Cambodia 6 months ago. She has smoked one pack of cigarettes daily for 15 years. Her temperature is 37.0˚C (98.6°F), pulse is 72/min, and blood pressure is 125/70 mm Hg. On physical examination, tiny blood vessels are noted on the face and arms. Lung auscultation shows bilateral wheezing. The abdomen is soft and nondistended. There is localized tenderness to the right lower quadrant but no rebound tenderness or guarding. Laboratory studies show: Leukocyte count4600/mm3 Segmented neutrophils61%Eosinophils2%Platelet count254,000/mm3Hemoglobin13.1 g/dLSerumAST110 IU/LALT128 IU/LC-reactive protein8 mg/dL (N = 0-10) Which of the following is the most likely diagnosis?

Carcinoid tumor

A previously healthy 67-year-old man comes to the physician because of a history of recurrent right lower abdominal pain for the past 2 years. A CT scan shows a 1.2-cm (0.47-in) mass located in the terminal ileum. He undergoes surgical removal of the mass. A photomicrograph of the resected specimen is shown. Cells from this tissue are most likely to stain positive for which of the following?

Chromogranin A

A 67-year-old woman comes to the physician because of a 5-day history of episodic abdominal pain, nausea, and vomiting. She has coronary artery disease and type 2 diabetes mellitus. She takes aspirin, metoprolol, and metformin. She is 163 cm (5 ft 4 in) tall and weighs 91 kg (200 lb); her BMI is 34 kg/m2. Her temperature is 38.1°C (100.6°F). Physical examination shows dry mucous membranes, abdominal distension, and hyperactive bowel sounds. Ultrasonography of the abdomen shows air in the biliary tract. This patient's symptoms are most likely caused by obstruction at which of the following locations?

Distal ileum

A 40-year-old man comes to the physician because of a 5-month history of watery diarrhea and episodic crampy abdominal pain. He has no fever, nausea, or vomiting. Over the past 6 months, he has had a 1.8-kg (4-lb) weight loss, despite experiencing no decrease in appetite. His wife has noticed that sometimes his face and neck become red after meals or when he is in distress. A year ago, he was diagnosed with asthma. He has hypertension. Current medications include an albuterol inhaler and enalapril. He drinks one beer daily. His temperature is 36.7°C (98.0°F), pulse is 85/min, and blood pressure is 130/85 mm Hg. The lungs are clear to auscultation. A grade 2/6 systolic murmur is heard best at the left sternal border and fourth intercostal space. The abdomen is soft, and there is mild tenderness to palpation with no guarding or rebound. The remainder of the physical examination shows no abnormalities. A complete blood count is within the reference range. Without treatment, this patient is at greatest risk for which of the following conditions?

Dementia

A 31-year-old man comes to the physician because of a 2-day history of abdominal pain and diarrhea. He reports that his stools are streaked with blood and mucus. He returned from a vacation in the Philippines 3 weeks ago. His vital signs are within normal limits. Abdominal examination shows hyperactive bowel sounds. A photomicrograph of a trichrome-stained wet mount of a stool specimen is shown. Which of the following organisms is the most likely cause of this patient's symptoms?

Entamoeba histolytica

A 2-day-old male newborn is brought to the emergency department by his mother because of irritability and vomiting for 2 hours. During this period, he has vomited bilious fluid three times. He has not yet passed stool. The mother has breastfed the newborn every 2 hours. He has wet two diapers during the last 2 days. He was born at term and was delivered at home. Pregnancy and delivery were uncomplicated. The mother had no prenatal care during pregnancy. The patient currently weighs 3100 g (6 lb 13 oz) and is 50 cm (19.6 in) in length. The newborn appears restless. His temperature is 37.3°C (99.14°F), pulse is 166/min, respirations are 60/min, and blood pressure is 60/45 mm Hg. There is no redness or warmth around the umbilical cord stump. Cardiopulmonary examination shows no abnormalities. Bowel sounds are sparse. The abdomen is distended. Digital rectal examination shows no abnormalities. An x-ray of the abdomen with contrast shows dilated small bowel loops, a microcolon, and a mixture of gas and meconium located in the right lower quadrant. A nasogastric tube is placed and fluid resuscitation is begun. Which of the following is the most appropriate next step in the management of this

Gastrografin enema

A 54-year-old man comes to the emergency department because of a 2-day history of increasingly severe abdominal pain, nausea, and bilious vomiting. His last bowel movement was yesterday and he has not passed flatus since then. He underwent an appendectomy at the age of 39. Medical history is remarkable for type 2 diabetes mellitus, hypertension, psoriasis, and chronic back pain. His medications are metformin, ramipril, ibuprofen, and a corticosteroid cream. He drinks two beers daily. He is 176 cm (5 ft 9 in) tall and weighs 108 kg (240 lb); BMI is 35 kg/m2. His temperature is 36.8°C (98.4°F), respirations are 15/min, pulse is 90/min, and blood pressure is 112/67 mm Hg. Examination shows thick, scaly plaques over both elbows and knees. Abdominal examination shows three well-healed laparoscopic scars. The abdomen is distended and there are frequent, high-pitched bowel sounds on auscultation. Digital rectal examination shows an empty rectum. Laboratory studies show: Hematocrit44%Leukocyte count9000/mm3Platelet count225,000/mm3SerumNa+139 mEq/LK+4.1 mEq/LCl−101 mEq/LHCO3− 26 mEq/LGlucose95 mg/dLCreatinine1.1 mg/dLAlkaline phosphatase78 U/LAspartate aminotransferase (AST, GOT)19 U/LAlan

History of abdominal surgery

A 75-year-old man comes to the physician because of a 2-month history of intermittent bright red blood in his stool, progressive fatigue, and a 5-kg (11-lb) weight loss. He appears thin and fatigued. Physical examination shows conjunctival pallor. Hemoglobin concentration is 7.5 g/dL and MCV is 77 μm3. Results of fecal occult blood testing are positive. A colonoscopy shows a large, friable mass in the anal canal proximal to the pectinate line. Primary metastasis to which of the following lymph nodes is most likely in this patient?

Internal iliac

A 15-year-old girl is brought to the physician by her mother for a 2-day history of abdominal pain, nausea, vomiting, diarrhea, and decreased appetite. Her last menstrual period was 3 weeks ago. Her temperature is 38.1°C (100.6°F). Abdominal examination shows tenderness to palpation with guarding in the right lower quadrant. Laboratory studies show a leukocyte count of 12,600/mm3. Which of the following is the most likely underlying cause of this patient's condition?

Lymphatic tissue hyperplasia

A 38-year-old man is brought to the emergency room because of diarrhea for 2 days. He has abdominal cramps and has also noticed that his stools have a dark red tint. He returned from a trip to Mexico 3 weeks ago, where he completed a marathon. He has a history of mild anemia. He does not smoke and drinks 3-4 beers on weekends. He takes fish oil, a multivitamin, and iron supplements to improve his athletic performance. His temperature is 38.8°C (101.8°F), pulse is 65/min, and blood pressure is 120/75 mm Hg. Lungs are clear to auscultation. Cardiac examination shows no abnormalities. There is mild tenderness to palpation of the left lower quadrant without rebound or guarding. Laboratory studies show: Hematocrit37.1%Leukocyte count4500/mm3Platelet count240,000/mm3SerumNa+136 mEq/LK+4.5 mEq/LCl-102 mEq/LHCO3-26 mEq/LUrea nitrogen14 mg/dLCreatinine1.2 mg/dL Microscopic examination of the stools shows organisms with ingested erythrocytes. In addition to supportive therapy, which of the following is the most appropriate next step in management?

Metronidazole

A 46-year-old woman comes to the physician because of a 3-day history of diarrhea and abdominal pain. She returned from a trip to Egypt 4 weeks ago. Her vital signs are within normal limits. There is mild tenderness in the right lower quadrant. Stool studies show occult blood and unicellular organisms with engulfed erythrocytes. Which of the following is the most appropriate initial pharmacotherapy for this patient?

Metronidazole

A 63-year-old man is brought to the emergency department for evaluation of abdominal pain. The pain started four days ago and is now a diffuse crampy pain with an intensity of 6/10. The patient has nausea and has vomited twicetoday. His last bowel movement was three days ago. He has a history of hypertension and recurrent constipation. Five years ago, he underwent emergency laparotomy for a perforated duodenal ulcer. His father died of colorectal cancer at the age of 65 years. The patient has been smoking one pack of cigarettes daily for the past 40 years. Current medications include lisinopril and lactulose. His temperature is 37.6°C (99.7°F), pulse is 89/min, and blood pressure is 120/80 mm Hg. Abdominal examination shows distention and mild tenderness to palpation. There is no guarding or rebound tenderness. Bowel sounds are high-pitched. Digital rectal examination shows no abnormalities. An x-ray of the abdomen is shown. In addition to fluid resuscitation, which of the following is the most appropriate next step in the management of this patient?

Nasogastric tube placement and bowel rest

A 28-year-old woman comes to the emergency department because of a 6-day history of abdominal pain, fever, vomiting, and decreased appetite. Her pain started as dull and diffuse but has progressed to a sharp pain on her right side. She did not seek medical attention earlier because she has no medical insurance and "was waiting for the pain to disappear." She has no history of serious illness. She is sexually active with one male partner and uses condoms consistently. Her temperature is 38.2°C (100.8°F), pulse is 88/min, respirations are 18/min, and blood pressure is 125/75 mm Hg. Abdominal examination shows tenderness to palpation of the right lower quadrant. Her hemoglobin concentration is 13.6 g/dL, leukocyte count is 16,500/mm3, and platelet count is 215,000/mm3. A serum pregnancy test is negative. CT scan of the abdomen shows an edematous appendix with a 5-cm periappendiceal fluid collection. The patient is placed on bowel rest and started on IV fluids. In addition to administering intravenous antibiotics, which of the following is the most appropriate next step in management?

Percutaneous drainage

A 38-year-old woman comes to the physician because of a 4-month history of crampy abdominal pain, recurrent watery diarrhea, and a 2.5-kg (5.5-lb) weight loss. Her husband has noticed that after meals, her face and neck sometimes become red, and she develops shortness of breath and starts wheezing. Examination shows a grade 3/6systolic murmur heard best at the left lower sternal border. The abdomen is soft, and there is mild tenderness to palpation with no guarding or rebound. Without treatment, this patient is at greatest risk of developing which of the following conditions?

Pigmented dermatitis

A 40-year-old woman comes to the physician because of a 2-week history of anal pain that occurs during defecation and lasts for several hours. She reports that she often strains during defecation and sees bright red blood on toilet paper after wiping. She typically has 3 bowel movements per week. Physical examination shows a longitudinal, perianal tear. This patient's symptoms are most likely caused by tissue injury in which of the following locations?

Posterior midline of the anal canal, distal to the pectinate line

A 45-year-old woman comes to the physician because of fatigue, abdominal cramps, watery diarrhea, and a weight loss of 4 kg (8.8 lb) over the last 4 months. She has recently avoided drinking alcohol and eating spicy food because it worsens her diarrhea and causes episodes of heart palpitations and reddening of the face and neck. She takes lisinopril for hypertension. Her temperature is 36.5°C (97.7°F), pulse is 98/min, and blood pressure is 149/90 mm Hg. The abdomen is soft and there is mild tenderness to palpation with no guarding or rebound. Laboratory studies show an increased urine 5-hydroxyindoleacetic acid concentration. Further evaluation of this patient will most likely show which of the following?

Pulmonic valve stenosis

Four days after having been admitted to the hospital for a pulmonary contusion and whiplash injury sustained in a motor vehicle collision, a 66-year-old woman complains of severe pain in her right flank, abdominal bloating, and nausea. She has also vomited twice in the past 2 hours. Her musculoskeletal pain due to the motor vehicle collision had been well controlled with acetaminophen every 6 hours but the medication provides no relief for the flank pain. She underwent umbilical hernia repair surgery 2 years ago. Her temperature is 36.5°C (97.7°F), pulse is 99/min, respirations are 17/min, and blood pressure is 102/72 mm Hg. After administration of 0.5 L of crystalloid fluids, blood pressure improves to 118/79 mm Hg. Multiple ecchymoses are present over the anterior abdominal wall in a pattern that follows the course of a seatbelt and there are new ecchymoses over the flanks bilaterally. Bowel sounds are absent. There is tenderness to palpation in all four quadrants with voluntary guarding. Her hemoglobin is 7.9 g/dL, leukocyte count is 8500/mm3, platelet count is 350,000/mm3, prothrombin time is 11 seconds, and activated partial thromboplastin time is 33 seconds. An x-ray of the abdom

Retroperitoneal hemorrhage

A 65-year-old woman with atrial fibrillation comes to the emergency department because of sudden-onset severe abdominal pain, nausea, and vomiting for the past 2 hours. She has smoked a pack of cigarettes daily for the past 25 years. Her pulse is 110/min and blood pressure is 141/98 mm Hg. Abdominal examination shows diffuse abdominal tenderness without guarding or rebound. A CT angiogram of the abdomen confirms an acute occlusion in the inferior mesenteric artery. Which of the following structures of the gastrointestinal tract is most likely to be affected in this patient?

Rectosigmoid colon

Four days after undergoing a total abdominal hysterectomy for atypical endometrial hyperplasia, a 59-year-old woman reports abdominal bloating and discomfort. She has also had nausea without vomiting. She has no appetite despite not having eaten since the surgery and drinking only sips of water. Her postoperative pain has been well controlled on a hydromorphone patient-controlled analgesia (PCA) pump. Her indwelling urinary catheter was removed on the second postoperative day and she is now voiding freely. Although she lays supine in bed for most of the day, she is able to walk around the hospital room with the help of a physical therapist. Her temperature is 36.5°C (97.7°F), pulse is 84/min, respirations are 10/min, and blood pressure is 132/92 mm Hg. She is 175 cm (5 ft 9 in) tall and weighs 115 kg(253 lb); BMI is 38 kg/m2. Examination shows a mildly distended, tympanic abdomen; bowel sounds are absent. Laboratory studies are within normal limits. An x-ray of the abdomen shows uniform distribution of gas in the small bowel, colon, and rectum without air-fluid levels. Which of the following is the most appropriate next step in the management of this patient?

Reduce use of opioid therapy

A 57-year-old man comes to the physician for a follow-up examination. Two months ago, he was diagnosed with an anal fissure and started treatment with lidocaine gel, nifedipine ointment, and daily sitz baths. The patient reports perianal pruritis and sharp anal pain that increases during defecation; he has not had rectal bleeding. Medical history is remarkable for hypercholesterolemia and chronic constipation. His mother was diagnosed with colorectal cancer at the age of 74 years. Medications include atorvastatin and lactulose. He does not smoke cigarettes and drinks two beers daily. He has recently started following a high-fiber diet. Vital signs are within normal limits. Physical examination shows a deep, longitudinal perianal tear in the posterior midline with wide, raised edges and multiple skin tags. Rectosigmoid endoscopy shows no abnormalities. Which of the following is the most appropriate next step in management?

Refer the patient for surgical repair

A 38-year-old man comes to the physician because of a 2-week history of severe pain while passing stools. The stools are covered with bright red blood. He has been avoiding defecation because of the pain. Last year, he was hospitalized for pilonidal sinus surgery. He has had chronic lower back pain ever since he had an accident at his workplace 10 yearsago. The patient's father was diagnosed with colon cancer at the age of 62 years. Current medications include oxycodone and gabapentin. He is 163 cm (5 ft 4 in) tall and weighs 100 kg (220 lb); BMI is 38 kg/m2. Vital signs are within normal limits. The abdomen is soft and nontender. Digital rectal examination was not performed because of severe pain. His hemoglobin concentration is 16.3 mg/dL and his leukocyte count is 8300/mm3. Which of the following is the most appropriate next step in management?

Sitz baths and topical nifedipine

A 24-year-old woman comes to the emergency department because of abdominal pain, fever, nausea, and vomiting for 12 hours. Her abdominal pain was initially dull and diffuse but has progressed to a sharp pain on the lower right side. Two years ago she had to undergo right salpingo-oophorectomy after an ectopic pregnancy. Her temperature is 38.7°C (101.7°F). Physical examination shows severe right lower quadrant tenderness with rebound tenderness; bowel sounds are decreased. Laboratory studies show leukocytosis with left shift. An abdominal CT scan shows a distended, edematous appendix. The patient is taken to the operating room for an appendectomy. During the surgery, the adhesions from the patient's previous surgery make it difficult for the resident physician to identify the appendix. Her attending mentions that she should use a certain structure for guidance to locate the appendix. The attending is most likely referring to which of the following structures?

Teniae coli

A 34-year-old man comes to the physician because of palpitations, shortness of breath, diarrhea, and abdominal cramps for 2 months. Physical examination shows cutaneous flushing of the face. Auscultation of the chest shows bilateral wheezing. A 24-hour urine collection shows increased 5-hydroxyindoleacetic acid (5-HIAA) concentration. A contrast-enhanced CT scan of the abdomen shows an intestinal tumor with extensive metastasis to the liver. A diagnosis of an inoperable disease is made and the patient is started on treatment with octreotide. Six weeks later, the patient's symptoms have improved except for his abdominal pain and frequent loose stools. The physician suggests enrolling the patient in a trial to test additional treatment with a new drug that has been shown to improve symptoms in other patients with the same condition. The expected beneficial effect of this new drug is most likely caused by inhibition of which of the following?

Tryptophan hydroxylase

A 38-year-old woman comes to the physician because of a 10-month history of nonbloody diarrhea and recurrent episodes of flushing and wheezing. She does not take any medications. Physical examination shows a hyperpigmented rash around the base of her neck. Cardiac examination shows a grade 3/6, holosystolic murmur at the left lower sternal border. Echocardiography shows right-sided endocardial and valvular fibrosis with moderate tricuspid regurgitation; there are no septal defects or left-sided valvular defects. Urinalysis shows increased 5-hydroxyindoleacetic acid concentration. Which of the following is the most likely explanation for this patient's symptoms?

Tumor in the terminal ileum with hepatic metastasis