The Gastrointestinal confusions that cost the most Step 1 points

Gastrointestinal look-alikes cost points because their symptoms often overlap. This post walks you through each pair and the clue that separates them.

Crohn disease vs Ulcerative colitis

Both can cause bloody diarrhea, weight loss, and extraintestinal disease. Look at depth and distribution instead of starting with diarrhea. Transmural skip lesions, granulomas, or disease from mouth to anus point to Crohn disease, while continuous mucosal disease beginning in the rectum points to ulcerative colitis. Do not let shared symptoms distract you from rectal involvement and the endoscopy or biopsy pattern.

Crohn disease vs Ulcerative colitis Crohn: transmural, skip lesions, granulomas, mouth to anus. UC: continuous mucosal disease from the rectum, no granulomas. Open the comparison and video →

Hepatitis A vs Hepatitis E

Both cause acute hepatitis through fecal-oral spread. Food, daycare, close contact, or lack of vaccination point to hepatitis A, while contaminated water or third-trimester pregnancy point to hepatitis E. The trap is that both are usually acute in healthy hosts, but hepatitis E can persist in immunosuppressed patients.

Hepatitis A vs Hepatitis E Both are fecal-oral; contaminated water and third-trimester fulminant-risk push hepatitis E. Open the comparison and video →

Gastric ulcer vs Duodenal ulcer

Both are peptic ulcers that can cause epigastric pain. Pain that worsens with meals and may lead to early satiety or weight loss points to a gastric ulcer, while pain that improves with meals and returns hours later or at night points to a duodenal ulcer. The trap is that every gastric ulcer needs biopsy and follow-up endoscopy to exclude gastric adenocarcinoma, while duodenal ulcers are almost never malignant. Use the meal pattern first, then remember the need for malignancy exclusion with a gastric ulcer.

Gastric ulcer vs Duodenal ulcer Gastric ulcer: pain worsens with food and weight drops; duodenal ulcer: pain eases with food and wakes the patient when the stomach is empty. Open the comparison and video →

Chronic hepatitis B vs Chronic hepatitis C

Both can cause chronic hepatitis, cirrhosis, and hepatocellular carcinoma. Persistent HBsAg with anti-HBc IgG points to chronic hepatitis B, while persistent HCV RNA after exposure points to chronic hepatitis C. The trap is relying on the shared outcomes instead of identifying the viral test and chronicity rule. Remember that HBV chronicity risk is highest after perinatal infection, while HCV commonly persists.

Chronic hepatitis B vs Chronic hepatitis C HBV chronicity depends strongly on age at infection and HBsAg persistence; HCV commonly persists and is confirmed by RNA. Open the comparison and video →

Hemochromatosis vs Wilson disease

Both can cause liver disease through inherited metal accumulation. Iron overload with bronze skin, diabetes, high ferritin, and high transferrin saturation points to hemochromatosis. Copper accumulation with neuropsychiatric changes, a movement disorder, low ceruloplasmin, or Kayser-Fleischer rings points to Wilson disease. The trap is focusing on the liver disease instead of identifying the metal pattern and extrahepatic organ clues.

Hemochromatosis vs Wilson disease Iron overload with bronze diabetes points hemochromatosis; copper with neurologic or corneal clues points Wilson disease. Open the comparison and video →

Primary biliary cholangitis vs Primary sclerosing cholangitis

Both can cause cholestatic disease with pruritus, elevated alkaline phosphatase, and progression to cirrhosis. Antimitochondrial antibodies and destruction of small intrahepatic bile ducts point to primary biliary cholangitis. Ulcerative colitis, multifocal strictures, and beading of the intrahepatic and extrahepatic ducts point to primary sclerosing cholangitis. The trap is relying on shared cholestatic findings instead of checking the antibody profile and duct anatomy.

Primary biliary cholangitis vs Primary sclerosing cholangitis PBC is small intrahepatic ducts plus antimitochondrial antibody; PSC is beaded intra/extrahepatic ducts plus ulcerative colitis association. Open the comparison and video →

Acute pancreatitis vs Chronic pancreatitis

Both can cause epigastric pain that radiates to the back. Sudden severe pain with nausea, vomiting, and lipase elevation points to acute pancreatitis. Recurrent chronic pain with fibrosis, calcifications, steatorrhea, fat-soluble vitamin deficiency, or diabetes points to chronic pancreatitis. The trap is ignoring the timeline and the signs of exocrine or endocrine failure.

Acute pancreatitis vs Chronic pancreatitis Acute pancreatitis is sudden enzyme-driven inflammation; chronic pancreatitis is fibrotic insufficiency with calcifications and malabsorption. Open the comparison and video →

Achalasia vs Diffuse esophageal spasm

Both can cause dysphagia and chest discomfort. Dysphagia to solids and liquids with impaired lower esophageal sphincter relaxation and bird-beak narrowing points to achalasia. Intermittent chest pain and dysphagia with uncoordinated contractions and a corkscrew appearance point to diffuse esophageal spasm. The trap is missing whether the main problem is lower esophageal sphincter nonrelaxation or uncoordinated contraction.

Achalasia vs Diffuse esophageal spasm Achalasia is tight nonrelaxing LES with bird-beak narrowing; diffuse spasm is uncoordinated contraction with corkscrew appearance. Open the comparison and video →

Quick self-test

Name the diagnosis from the clue, then tap to check.

1. Skip lesions, transmural inflammation, fistulas, strictures, RLQ pain, or perianal disease.

   Crohn disease · Crohn disease vs Ulcerative colitis

2. Continuous mucosal inflammation beginning in the rectum with bloody diarrhea.

   Ulcerative colitis · Crohn disease vs Ulcerative colitis

3. Epigastric pain that improves with meals and returns hours later or at night.

   Duodenal ulcer · Gastric ulcer vs Duodenal ulcer

4. Copper accumulation with hepatic disease, neuropsychiatric changes, movement disorder, low ceruloplasmin, and Kayser-Fleischer rings.

   Wilson disease · Hemochromatosis vs Wilson disease

5. Chronic HBV is persistent HBsAg with anti-HBc IgG, with chronicity risk highest after perinatal infection.

   Chronic hepatitis B · Chronic hepatitis B vs Chronic hepatitis C

6. Chronic HCV is persistent HCV RNA after exposure, with high chronicity risk and no routine vaccine.

   Chronic hepatitis C · Chronic hepatitis B vs Chronic hepatitis C

7. Recurrent chronic epigastric pain with pancreatic fibrosis, calcifications, steatorrhea, fat-soluble vitamin deficiency, and diabetes.

   Chronic pancreatitis · Acute pancreatitis vs Chronic pancreatitis

8. Middle-aged woman with pruritus, fatigue, cholestatic labs, antimitochondrial antibodies, and small intrahepatic bile duct destruction.

   Primary biliary cholangitis · Primary biliary cholangitis vs Primary sclerosing cholangitis

9. Cholestatic disease associated with ulcerative colitis, multifocal strictures, and beading of intrahepatic and extrahepatic bile ducts.

   Primary sclerosing cholangitis · Primary biliary cholangitis vs Primary sclerosing cholangitis

10. Sudden severe epigastric pain radiating to the back with nausea/vomiting and lipase elevation, often from gallstones or alcohol.

    Acute pancreatitis · Acute pancreatitis vs Chronic pancreatitis

11. Iron overload with cirrhosis, diabetes, bronze skin, cardiomyopathy, arthropathy, high ferritin, and high transferrin saturation.

    Hemochromatosis · Hemochromatosis vs Wilson disease

12. Dysphagia to solids and liquids with regurgitation, bird-beak narrowing, and impaired lower esophageal sphincter relaxation.

    Achalasia · Achalasia vs Diffuse esophageal spasm

How to make these stick

Practice each pair with fresh questions until you identify the separating clue automatically. Keep returning to the one distinction that decides the answer.