USMLE Step 2 Quiz: Lower Gastrointestinal Disorders
20 questions · exam conditions
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Lower Gastrointestinal DisordersQuestion 1 of 20

A 45-year-old woman has hematochezia and colonoscopy shows continuous mucosal inflammation from rectum proximally; biopsy with crypt abscesses. What is the most likely diagnosis?

Ulcerative colitis
Irritable bowel syndrome
Celiac disease
Acute appendicitis
Diverticulitis
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USMLE Step 2 Quiz

USMLE Step 2 Quiz: Lower Gastrointestinal Disorders

Practice Lower Gastrointestinal Disorders in USMLE Step 2 with focused quiz questions that help you check what you know, review explanations, and build confidence with test-style prompts.

What this quiz covers

This quiz focuses on Lower Gastrointestinal Disorders, giving you a quick way to practice the rules, question types, and explanations that matter most for USMLE Step 2.

How to use this quiz

Try each quiz question before looking at the correct answer. Use the explanations to review missed ideas, then come back to similar questions until the pattern feels familiar.

All questions

Question 1

A 45-year-old woman has hematochezia and colonoscopy shows continuous mucosal inflammation from rectum proximally; biopsy with crypt abscesses. What is the most likely diagnosis?

  1. Ulcerative colitis (correct answer)
  2. Irritable bowel syndrome
  3. Celiac disease
  4. Acute appendicitis
  5. Diverticulitis
Explanation: This question tests the ability to diagnose and manage Lower Gastrointestinal Disorders, key for patient care in gastroenterology. Understanding common lower GI disorders involves recognizing symptoms, appropriate diagnostic tests, and management strategies. In the provided clinical vignette, the patient's history of hematochezia with colonoscopy showing continuous inflammation and crypt abscesses indicate ulcerative colitis. The correct answer, A, is justified by classic findings of UC, aligning with current guidelines for IBD diagnosis. Distractor B is incorrect due to IBS not causing inflammation or bleeding, often seen when overlooking endoscopic evidence. Teaching strategies include reinforcing guideline-based management, using case studies to illustrate typical presentations, and encouraging practice in ordering appropriate diagnostic tests. Emphasize the importance of differentiating similar GI conditions.

Question 2

80yo, distension, crampy pain, obstipation. Imaging: sigmoid volvulus; no peritonitis. Best initial step?

  1. Endoscopic decompression only (correct answer)
  2. Emergent sigmoid colectomy
  3. Barium enema with reduction
  4. Intravenous antibiotics alone
Explanation: Nonoperative endoscopic decompression is the best initial step for sigmoid volvulus without peritonitis; it relieves obstruction and lets you assess bowel viability. Emergent colectomy is tempting but reserved for peritonitis, ischemia, or failure of endoscopic detorsion. Barium enema risks perforation and antibiotics alone don't fix the twist.

Question 3

28yo ulcerative colitis flare: 12 bloody stools/day, HR 120. Which finding most strongly warrants urgent colectomy?

  1. Toxic megacolon with dilation
  2. More than 10 bloody stools/day
  3. Perforation visible on CT scan (correct answer)
  4. Drop in hemoglobin to 9 g/dL
Explanation: Perforation is a definitive surgical emergency: it means bowel wall disruption with spillage and peritonitis, so urgent colectomy is mandatory. Toxic megacolon with dilation may still be managed medically first if not worsening, and more than 10 bloody stools or a hemoglobin drop to 9 are severity markers but not absolute surgical indications.

Question 4

68yo, fever, pain, vomiting. CT: sigmoid diverticulitis, fat stranding, no abscess or perforation. Best management?

  1. Outpatient oral antibiotics
  2. Bowel rest and IV antibiotics (correct answer)
  3. Emergency sigmoid resection
  4. Colonoscopy with decompression
Explanation: Fever with vomiting and CT showing diverticulitis without abscess or perforation is acute uncomplicated diverticulitis, but vomiting prevents reliable oral therapy, so bowel rest with IV antibiotics is appropriate. Outpatient oral antibiotics are tempting for uncomplicated disease, but this patient cannot tolerate PO intake and has systemic symptoms, so inpatient IV treatment is safer. No surgery or colonoscopy is indicated.

Question 5

68yo on antibiotics has watery diarrhea and positive C. difficile toxin. Which finding indicates fulminant infection?

  1. Hypotension with septic shock (correct answer)
  2. Elevated WBC count to 16,000
  3. Elevated creatinine 1.5 mg/dL
  4. Pseudomembranes on endoscopy
Explanation: Hypotension with septic shock marks end-organ hypoperfusion from severe C. difficile colitis, defining fulminant infection. A WBC of 16,000 or creatinine of 1.5 suggests severe but not fulminant disease, and pseudomembranes simply confirm C. diff colitis rather than fulminant course.

Question 6

A 45-year-old woman has 2 months of intermittent hematochezia and fatigue; family history of colon cancer; exam shows no external hemorrhoids; CBC: Hgb 9.8. Next test?

  1. Colonoscopy with biopsy to evaluate for colorectal neoplasia (correct answer)
  2. Reassure and treat presumptive hemorrhoids with topical therapy
  3. Start NSAIDs for abdominal discomfort and observe
  4. Order stool ova and parasite examination only
  5. Schedule follow-up in 1 year without further evaluation
Explanation: This question tests the ability to diagnose and manage Lower Gastrointestinal Disorders, key for patient care in gastroenterology. Understanding common lower GI disorders involves recognizing symptoms, appropriate diagnostic tests, and management strategies. In the provided clinical vignette, the patient's history of intermittent hematochezia, fatigue, family history, and anemia indicate possible colorectal cancer. The correct answer, A, is justified by colonoscopy for evaluation, aligning with current guidelines for bleeding with red flags. Distractor B is incorrect due to anemia requiring investigation beyond presumption, often seen when assuming hemorrhoids. Teaching strategies include reinforcing guideline-based management, using case studies to illustrate typical presentations, and encouraging practice in ordering appropriate diagnostic tests. Emphasize the importance of differentiating similar GI conditions.

Question 7

A 30-year-old woman with suspected IBS reports symptoms triggered by dairy and wheat; no weight loss or bleeding; normal vitals. Which diagnostic test should be ordered next?

  1. Screen for celiac disease with tissue transglutaminase IgA and total IgA (correct answer)
  2. Urgent colonoscopy for all patients with IBS symptoms
  3. CT angiography to localize occult bleeding
  4. Stool culture and ova/parasite testing regardless of chronicity
  5. ERCP to evaluate biliary obstruction
Explanation: This question tests the ability to diagnose and manage Lower Gastrointestinal Disorders, key for patient care in gastroenterology. Understanding common lower GI disorders involves recognizing symptoms, appropriate diagnostic tests, and management strategies. In the provided clinical vignette, the patient's history of IBS-like symptoms triggered by dairy and wheat indicate possible celiac disease overlap. The correct answer, A, is justified by screening for celiac in IBS with triggers, aligning with current guidelines for differential diagnosis. Distractor B is incorrect due to colonoscopy not first-line for IBS without alarms, often seen when escalating prematurely. Teaching strategies include reinforcing guideline-based management, using case studies to illustrate typical presentations, and encouraging practice in ordering appropriate diagnostic tests. Emphasize the importance of differentiating similar GI conditions.

Question 8

A 50-year-old woman with IBS has diarrhea-predominant symptoms triggered by stress and coffee; exam normal. What dietary modification should be recommended?

  1. Trial of low-FODMAP diet and avoidance of known triggers (correct answer)
  2. Increase insoluble fiber aggressively to stop diarrhea
  3. High-lactose diet to improve gut flora
  4. Gluten-free diet without evaluating for celiac disease
  5. Strict liquid-only diet for 2 weeks
Explanation: This question tests the ability to diagnose and manage Lower Gastrointestinal Disorders, key for patient care in gastroenterology. Understanding common lower GI disorders involves recognizing symptoms, appropriate diagnostic tests, and management strategies. In the provided clinical vignette, the patient's history of diarrhea-predominant IBS triggered by stress and coffee indicate dietary and lifestyle factors. The correct answer, A, is justified by low-FODMAP helping identify triggers, aligning with current guidelines for IBS management. Distractor B is incorrect due to insoluble fiber worsening diarrhea, often seen when misapplying constipation advice. Teaching strategies include reinforcing guideline-based management, using case studies to illustrate typical presentations, and encouraging practice in ordering appropriate diagnostic tests. Emphasize the importance of differentiating similar GI conditions.

Question 9

A 30-year-old woman with IBS has frequent loose stools and urgency during exams; no alarm features; normal labs. What is the most appropriate initial management?

  1. Dietary trigger avoidance and stress management with symptom-directed therapy (correct answer)
  2. Empiric broad-spectrum antibiotics for presumed infection
  3. Immediate colectomy due to risk of perforation
  4. Chronic NSAID therapy for abdominal pain control
  5. Hospitalization for IV fluids despite stable hydration
Explanation: This question tests the ability to diagnose and manage Lower Gastrointestinal Disorders, key for patient care in gastroenterology. Understanding common lower GI disorders involves recognizing symptoms, appropriate diagnostic tests, and management strategies. In the provided clinical vignette, the patient's history of loose stools and urgency with stress in IBS indicate diarrhea-predominant type. The correct answer, A, is justified by lifestyle and symptomatic management first, aligning with current guidelines for IBS. Distractor B is incorrect due to no evidence of infection, often seen when assuming infectious cause in chronic cases. Teaching strategies include reinforcing guideline-based management, using case studies to illustrate typical presentations, and encouraging practice in ordering appropriate diagnostic tests. Emphasize the importance of differentiating similar GI conditions.

Question 10

A 35-year-old traveler has fever, tenesmus, and bloody diarrhea; stool leukocytes positive; no hypotension. Which diagnostic test should be ordered next?

  1. Stool culture with Shiga toxin testing (correct answer)
  2. Hydrogen breath test for lactose intolerance
  3. CT angiography of the abdomen and pelvis
  4. Screening colonoscopy without stool studies
  5. Serum anti-tissue transglutaminase IgA level
Explanation: This question tests the ability to diagnose and manage Lower Gastrointestinal Disorders, key for patient care in gastroenterology. Understanding common lower GI disorders involves recognizing symptoms, appropriate diagnostic tests, and management strategies. In the provided clinical vignette, the patient's history of fever, tenesmus, bloody diarrhea, and positive stool leukocytes indicate invasive bacterial diarrhea. The correct answer, A, is justified by identifying pathogens like E. coli or Shigella, aligning with current guidelines for dysentery-like symptoms. Distractor C is incorrect due to no indication of vascular issues, often seen when mistaking for ischemic colitis. Teaching strategies include reinforcing guideline-based management, using case studies to illustrate typical presentations, and encouraging practice in ordering appropriate diagnostic tests. Emphasize the importance of differentiating similar GI conditions.

Question 11

A 50-year-old woman with IBS reports worsening diarrhea after starting sertraline; no fever or blood; exam benign. Which medication should be adjusted or discontinued?

  1. Discontinue sertraline due to possible medication-associated diarrhea (correct answer)
  2. Stop acetaminophen due to risk of colitis
  3. Stop inhaled albuterol due to GI adverse effects
  4. Stop lisinopril due to constipation risk
  5. Stop loratadine due to increased stool frequency
Explanation: This question tests the ability to diagnose and manage Lower Gastrointestinal Disorders, key for patient care in gastroenterology. Understanding common lower GI disorders involves recognizing symptoms, appropriate diagnostic tests, and management strategies. In the provided clinical vignette, the patient's history of worsening diarrhea after starting sertraline indicate medication side effect in IBS. The correct answer, A, is justified by SSRIs commonly causing diarrhea, aligning with current guidelines for medication review. Distractor B is incorrect due to acetaminophen not typically causing colitis, often seen when confusing analgesics. Teaching strategies include reinforcing guideline-based management, using case studies to illustrate typical presentations, and encouraging practice in ordering appropriate diagnostic tests. Emphasize the importance of differentiating similar GI conditions.

Question 12

A 35-year-old man has acute diarrhea after travel; stool Shiga toxin positive, creatinine rising. Which complication is most likely to occur?

  1. Toxic megacolon requiring emergent colectomy
  2. Hemolytic uremic syndrome with thrombocytopenia (correct answer)
  3. Primary sclerosing cholangitis
  4. Colorectal adenocarcinoma within weeks
  5. Acute pancreatitis from gallstone obstruction
Explanation: This question tests the ability to diagnose and manage Lower Gastrointestinal Disorders, key for patient care in gastroenterology. Understanding common lower GI disorders involves recognizing symptoms, appropriate diagnostic tests, and management strategies. In the provided clinical vignette, the patient's history of acute diarrhea after travel with positive Shiga toxin and rising creatinine indicate E. coli O157:H7 infection. The correct answer, B, is justified by risk of HUS in shiga-toxin producing infections, aligning with current guidelines for enterohemorrhagic E. coli. Distractor A is incorrect due to no evidence of toxic megacolon, often seen when confusing with C. difficile. Teaching strategies include reinforcing guideline-based management, using case studies to illustrate typical presentations, and encouraging practice in ordering appropriate diagnostic tests. Emphasize the importance of differentiating similar GI conditions.

Question 13

A 50-year-old woman with IBS has 3 months of worsening watery diarrhea and nocturnal symptoms; weight loss; normal exam; basic labs normal. Which diagnostic test should be ordered next?

  1. Colonoscopy with biopsies to evaluate for organic disease (correct answer)
  2. Empiric antibiotics for presumed IBS flare
  3. Reassurance and no further workup due to IBS history
  4. Abdominal radiograph to assess stool burden only
  5. Immediate loperamide and follow-up only if bleeding occurs
Explanation: This question tests the ability to diagnose and manage Lower Gastrointestinal Disorders, key for patient care in gastroenterology. Understanding common lower GI disorders involves recognizing symptoms, appropriate diagnostic tests, and management strategies. In the provided clinical vignette, the patient's history of worsening watery diarrhea, nocturnal symptoms, and weight loss indicate possible inflammatory or malabsorptive disorder beyond IBS. The correct answer, A, is justified by ruling out organic causes like IBD or cancer, aligning with current guidelines for alarm symptoms in IBS. Distractor C is incorrect due to presence of red flags requiring evaluation, often seen when underestimating nocturnal symptoms. Teaching strategies include reinforcing guideline-based management, using case studies to illustrate typical presentations, and encouraging practice in ordering appropriate diagnostic tests. Emphasize the importance of differentiating similar GI conditions.

Question 14

A 50-year-old woman with IBS has chronic diarrhea; BMP shows hypokalemia; orthostasis on exam. Which complication is most likely to occur if untreated?

  1. Cardiac arrhythmias due to electrolyte abnormalities (correct answer)
  2. Portal hypertension from chronic diarrhea
  3. Acute appendicitis from gut dysmotility
  4. Aortic dissection due to dehydration
  5. Hypercalcemia from volume depletion
Explanation: This question tests the ability to diagnose and manage Lower Gastrointestinal Disorders, key for patient care in gastroenterology. Understanding common lower GI disorders involves recognizing symptoms, appropriate diagnostic tests, and management strategies. In the provided clinical vignette, the patient's history of chronic diarrhea with hypokalemia and orthostasis indicate electrolyte imbalance from IBS. The correct answer, A, is justified by hypokalemia risking arrhythmias, aligning with current guidelines for complications. Distractor B is incorrect due to no link to portal hypertension, often seen when confusing with liver disease. Teaching strategies include reinforcing guideline-based management, using case studies to illustrate typical presentations, and encouraging practice in ordering appropriate diagnostic tests. Emphasize the importance of differentiating similar GI conditions.

Question 15

A 67-year-old man has constipation with abdominal distension and vomiting; tympany; no flatus; X-ray suggests large-bowel obstruction. Which diagnostic test should be ordered next?

  1. CT abdomen and pelvis with contrast to evaluate obstruction etiology (correct answer)
  2. Stool ova and parasite examination
  3. Fecal calprotectin level
  4. Hydrogen breath test for SIBO
  5. Screening colonoscopy without imaging
Explanation: This question tests the ability to diagnose and manage Lower Gastrointestinal Disorders, key for patient care in gastroenterology. Understanding common lower GI disorders involves recognizing symptoms, appropriate diagnostic tests, and management strategies. In the provided clinical vignette, the patient's history of constipation with distension, vomiting, and X-ray suggesting obstruction indicate mechanical obstruction. The correct answer, A, is justified by CT evaluating cause like tumor, aligning with current guidelines for suspected obstruction. Distractor E is incorrect due to colonoscopy risking perforation in obstruction, often seen when prioritizing endoscopy prematurely. Teaching strategies include reinforcing guideline-based management, using case studies to illustrate typical presentations, and encouraging practice in ordering appropriate diagnostic tests. Emphasize the importance of differentiating similar GI conditions.

Question 16

A 30-year-old woman with IBS asks about diet; symptoms worsen with onions, beans, and certain fruits; exam normal. What dietary modification should be recommended?

  1. Trial of low-FODMAP diet with gradual reintroduction to identify triggers (correct answer)
  2. High-fiber diet with large bran intake regardless of symptoms
  3. Zero-FODMAP diet indefinitely without reintroduction
  4. High-fat diet to slow intestinal transit
  5. Daily fruit juice cleanse as primary therapy
Explanation: This question tests the ability to diagnose and manage Lower Gastrointestinal Disorders, key for patient care in gastroenterology. Understanding common lower GI disorders involves recognizing symptoms, appropriate diagnostic tests, and management strategies. In the provided clinical vignette, the patient's history of IBS worsening with onions, beans, and fruits indicate FODMAP sensitivity. The correct answer, A, is justified by low-FODMAP trial for symptom control, aligning with current guidelines for dietary management in IBS. Distractor C is incorrect due to indefinite restriction risking malnutrition, often seen when not planning reintroduction. Teaching strategies include reinforcing guideline-based management, using case studies to illustrate typical presentations, and encouraging practice in ordering appropriate diagnostic tests. Emphasize the importance of differentiating similar GI conditions.

Question 17

A 30-year-old woman has 6 months of alternating diarrhea and constipation with crampy pain relieved by defecation; high stress; exam and CBC normal. Most likely diagnosis?

  1. Irritable bowel syndrome (correct answer)
  2. Celiac disease
  3. Ulcerative colitis
  4. Acute infectious colitis
  5. Colon cancer
Explanation: This question tests the ability to diagnose and manage Lower Gastrointestinal Disorders, key for patient care in gastroenterology. Understanding common lower GI disorders involves recognizing symptoms, appropriate diagnostic tests, and management strategies. In the provided clinical vignette, the patient's history of alternating bowel habits, crampy pain relieved by defecation, and stress indicate irritable bowel syndrome. The correct answer, A, is justified by Rome criteria for IBS, aligning with current guidelines for functional disorders. Distractor E is incorrect due to no alarm features suggesting cancer, often seen when overinterpreting chronic symptoms. Teaching strategies include reinforcing guideline-based management, using case studies to illustrate typical presentations, and encouraging practice in ordering appropriate diagnostic tests. Emphasize the importance of differentiating similar GI conditions.

Question 18

A 45-year-old woman presents with painless hematochezia and lightheadedness; tachycardic; CBC shows Hgb 7.6; ongoing bleeding. What is the most appropriate initial management?

  1. IV fluid resuscitation and blood transfusion as indicated, then localization of bleeding (correct answer)
  2. Outpatient oral iron and reassurance only
  3. High-fiber diet and sitz baths for presumed hemorrhoids
  4. Empiric antibiotics for presumed infectious colitis
  5. Immediate loperamide to decrease stool frequency
Explanation: This question tests the ability to diagnose and manage Lower Gastrointestinal Disorders, key for patient care in gastroenterology. Understanding common lower GI disorders involves recognizing symptoms, appropriate diagnostic tests, and management strategies. In the provided clinical vignette, the patient's history of painless hematochezia with tachycardia and low Hgb indicate acute lower GI bleed. The correct answer, A, is justified by stabilization before localization, aligning with current guidelines for hemodynamic instability. Distractor B is incorrect due to instability precluding outpatient management, often seen when underestimating severity. Teaching strategies include reinforcing guideline-based management, using case studies to illustrate typical presentations, and encouraging practice in ordering appropriate diagnostic tests. Emphasize the importance of differentiating similar GI conditions.

Question 19

A 67-year-old man with CAD has constipation after starting oxycodone for back pain; no red flags; rectal exam shows hard stool. Which medication should be adjusted or discontinued?

  1. Reduce or replace opioid analgesic if feasible and add bowel regimen (correct answer)
  2. Stop aspirin because it causes constipation
  3. Stop atorvastatin due to ileus risk
  4. Stop metoprolol due to stool retention
  5. Stop nitroglycerin due to decreased motility
Explanation: This question tests the ability to diagnose and manage Lower Gastrointestinal Disorders, key for patient care in gastroenterology. Understanding common lower GI disorders involves recognizing symptoms, appropriate diagnostic tests, and management strategies. In the provided clinical vignette, the patient's history of constipation after starting oxycodone indicate opioid-induced constipation. The correct answer, A, is justified by opioids slowing motility, aligning with current guidelines for medication review. Distractor B is incorrect due to aspirin not causing constipation, often seen when confusing antiplatelets. Teaching strategies include reinforcing guideline-based management, using case studies to illustrate typical presentations, and encouraging practice in ordering appropriate diagnostic tests. Emphasize the importance of differentiating similar GI conditions.

Question 20

A 35-year-old man has acute watery diarrhea after travel; stool antigen positive for Giardia; bloating and foul-smelling stools. What is the most appropriate initial management?

  1. Oral vancomycin therapy
  2. Azithromycin single-dose therapy
  3. Metronidazole therapy with oral rehydration (correct answer)
  4. High-dose loperamide without antimicrobials
  5. Immediate colonoscopy with biopsies
Explanation: This question tests the ability to diagnose and manage Lower Gastrointestinal Disorders, key for patient care in gastroenterology. Understanding common lower GI disorders involves recognizing symptoms, appropriate diagnostic tests, and management strategies. In the provided clinical vignette, the patient's history of acute watery diarrhea after travel with positive Giardia antigen indicate giardiasis. The correct answer, C, is justified by metronidazole as first-line treatment, aligning with current guidelines for parasitic diarrhea. Distractor A is incorrect due to vancomycin targeting C. difficile, often seen when confusing with antibiotic-associated diarrhea. Teaching strategies include reinforcing guideline-based management, using case studies to illustrate typical presentations, and encouraging practice in ordering appropriate diagnostic tests. Emphasize the importance of differentiating similar GI conditions.