Internal Medicine Gastroenterology Disorders Questions and Answers — Questions and Answers
Question 1: A 32-year-old male is newly diagnosed with moderate-to-severe ileocolonic Crohn's disease. He has not received prior treatment. According to the most recent American Gastroenterological Association (AGA) guidelines, which of the following is the most appropriate initial therapeutic approach?
- Step-up therapy starting with oral mesalamine
- A prolonged course of oral corticosteroids as monotherapy
- Early initiation of an anti-TNF agent such as infliximab (Correct answer)
- A 12-week course of broad-spectrum antibiotics
Correct answer: Early initiation of an anti-TNF agent such as infliximab
Current AGA guidelines recommend early initiation of advanced therapies, such as anti-TNF agents (e.g., infliximab), for patients with moderate-to-severe Crohn's disease. This approach is favored over traditional 'step-up' therapy to achieve better long-term outcomes, including mucosal healing and reduced complications. Corticosteroids are used for induction but not for maintenance, oral mesalamine is generally ineffective for moderate-to-severe Crohn's, and antibiotics are reserved for specific complications like abscesses or fistulae.
Question 2: A 28-year-old woman presents with chronic diarrhea, bloating, and newly diagnosed iron deficiency anemia. Celiac disease is suspected. Which of the following is the most appropriate initial serologic test for this condition in an adult who is not IgA deficient?
- Anti-gliadin antibodies (AGA), IgG and IgA
- Tissue transglutaminase (tTG)-IgA antibody (Correct answer)
- Anti-endomysial antibodies (EMA), IgA
- Genetic testing for HLA-DQ2/DQ8
Correct answer: Tissue transglutaminase (tTG)-IgA antibody
The tissue transglutaminase (tTG)-IgA antibody test is the preferred single test for detecting celiac disease in adults and children over the age of two, due to its high sensitivity and specificity. Anti-endomysial (EMA) antibodies are highly specific but less sensitive and more operator-dependent. Anti-gliadin antibodies are no longer recommended for primary screening. Genetic testing is useful to rule out celiac disease but does not confirm a diagnosis.
Question 3: A 50-year-old man with a history of heavy alcohol use is admitted with severe epigastric pain radiating to the back and a serum lipase level five times the upper limit of normal. He is diagnosed with acute pancreatitis. Which of the following interventions is considered the cornerstone of early management?
- Prophylactic antibiotic administration
- Immediate ERCP with sphincterotomy
- Aggressive intravenous fluid resuscitation (Correct answer)
- Placement of a nasogastric tube for bowel rest
Correct answer: Aggressive intravenous fluid resuscitation
Aggressive early intravenous fluid resuscitation is the single most critical intervention and cornerstone of management in acute pancreatitis. It is crucial for maintaining pancreatic and systemic perfusion, thereby reducing the risk of complications like pancreatic necrosis and organ failure. Prophylactic antibiotics are not recommended for severe acute pancreatitis without evidence of infection. ERCP is indicated emergently only if there is concurrent cholangitis. Nasogastric tube placement is not routinely required unless there is intractable vomiting or severe ileus.
Question 4: A 62-year-old man with cirrhosis and ascites presents with a fever of 38.5°C (101.3°F) and diffuse abdominal pain. A diagnostic paracentesis is performed. Which of the following ascitic fluid findings is diagnostic for spontaneous bacterial peritonitis (SBP)?
- Serum-ascites albumin gradient (SAAG) > 1.1 g/dL
- Polymorphonuclear (PMN) leukocyte count of 350 cells/mm³ (Correct answer)
- Total protein > 2.5 g/dL
- Positive bacterial culture with a PMN count of 100 cells/mm³
Correct answer: Polymorphonuclear (PMN) leukocyte count of 350 cells/mm³
The diagnosis of spontaneous bacterial peritonitis (SBP) is established by an ascitic fluid polymorphonuclear (PMN) leukocyte count of ≥250 cells/mm³. Therefore, a count of 350 cells/mm³ is diagnostic and requires immediate initiation of empiric antibiotic therapy. A SAAG > 1.1 g/dL indicates portal hypertension but not infection. A positive culture with a low PMN count is termed bacterascites and may not require treatment if the patient is asymptomatic. Ascitic fluid protein levels are not used for diagnosing SBP.
Question 5: A 48-year-old patient requires treatment for a newly diagnosed *Helicobacter pylori* infection. The local clarithromycin resistance rate is known to be over 20%. According to the latest ACG guidelines, which of the following is a recommended first-line therapy?
- Clarithromycin-based triple therapy for 7 days
- Levofloxacin-based triple therapy for 10 days
- Bismuth quadruple therapy for 14 days (Correct answer)
- Dual therapy with a PPI and amoxicillin for 14 days
Correct answer: Bismuth quadruple therapy for 14 days
In regions where clarithromycin resistance is high (>15%), standard clarithromycin-based triple therapy is no longer recommended as a first-line treatment due to low eradication rates. The updated 2024 ACG guidelines strongly recommend bismuth quadruple therapy (a PPI, bismuth, tetracycline, and a nitroimidazole) for 14 days as a preferred first-line option. Levofloxacin-based regimens are typically reserved for salvage therapy, and dual therapy has inferior efficacy.
Question 6: A 46-year-old asymptomatic woman presents for a health maintenance visit. She reports that her father was diagnosed with colon cancer at age 54. According to current USPSTF and ACG guidelines, what is the most appropriate screening recommendation for this patient?
- Begin screening at age 50 with colonoscopy
- Begin screening now with a multi-target stool DNA test every 3 years
- Begin screening now with a colonoscopy (Correct answer)
- Begin screening at age 44 with an annual fecal immunochemical test (FIT)
Correct answer: Begin screening now with a colonoscopy
For individuals with a first-degree relative diagnosed with colorectal cancer before the age of 60, screening should begin at age 40, or 10 years younger than the age at diagnosis of the affected relative, whichever is earlier. In this case, 10 years before her father's diagnosis at age 54 would be age 44. Since the patient is 46, she is past the recommended start age and should begin screening now. Colonoscopy is the preferred screening modality in this higher-risk scenario.
A 32-year-old male is newly diagnosed with moderate-to-severe ileocolonic Crohn's disease.
He has not received prior treatment.
According to the most recent American Gastroenterological Association (AGA) guidelines, which of the following is the most appropriate initial therapeutic approach?