Gastrointestinal confusion pairs
38 Gastrointestinal topics students commonly mix up on Step 1, each with the fastest separator, a side-by-side comparison, and a free practice question.
- Crohn disease vs Ulcerative colitisCrohn: transmural, skip lesions, granulomas, mouth to anus. UC: continuous mucosal disease from the rectum, no granulomas.Video
- Hepatitis A vs Hepatitis EBoth are fecal-oral; contaminated water and third-trimester fulminant-risk push hepatitis E.Video
- Gastric ulcer vs Duodenal ulcerGastric ulcer: pain worsens with food and weight drops; duodenal ulcer: pain eases with food and wakes the patient when the stomach is…Video
- Active HBV infection vs HBV immunity patternsHBsAg means active infection; anti-HBs means immunity; anti-HBc tells natural exposure versus vaccine-only immunity.
- Chronic hepatitis B vs Chronic hepatitis CHBV chronicity depends strongly on age at infection and HBsAg persistence; HCV commonly persists and is confirmed by RNA.Video
- HBV-HDV coinfection vs HDV superinfectionCoinfection: simultaneous acute HBV and HDV that usually resolves; superinfection: HDV onto chronic HBV with high chronicity and rapid…
- Cirrhosis vs Acute liver failureCirrhosis is chronic portal-hypertension architecture; acute liver failure is rapid encephalopathy plus coagulopathy in acute injury.
- Alcohol-associated fatty liver disease vs Metabolic dysfunction-associated steatotic liver diseaseAlcohol exposure and AST:ALT near 2:1 point alcohol-associated disease; metabolic syndrome without alcohol points MASLD/NAFLD.
- Hemochromatosis vs Wilson diseaseIron overload with bronze diabetes points hemochromatosis; copper with neurologic or corneal clues points Wilson disease.Video
- Primary biliary cholangitis vs Primary sclerosing cholangitisPBC is small intrahepatic ducts plus antimitochondrial antibody; PSC is beaded intra/extrahepatic ducts plus ulcerative colitis association.Video
- Acute cholecystitis vs Common bile duct obstruction patternsCholecystitis is inflamed gallbladder with Murphy sign; choledocholithiasis is CBD stone; cholangitis is infected CBD obstruction with…
- Acute pancreatitis vs Chronic pancreatitisAcute pancreatitis is sudden enzyme-driven inflammation; chronic pancreatitis is fibrotic insufficiency with calcifications and…Video
- Pancreatic adenocarcinoma vs Pancreatic neuroendocrine tumorAdenocarcinoma is ductal obstruction and weight loss; neuroendocrine tumor is hormone syndrome or endocrine mass.
- Insulinoma vs Other functional pancreatic neuroendocrine tumorsInsulinoma: fasting hypoglycemia with high insulin and C-peptide; other pancreatic neuroendocrine tumors are named by their hormone…
- Achalasia vs Diffuse esophageal spasmAchalasia is tight nonrelaxing LES with bird-beak narrowing; diffuse spasm is uncoordinated contraction with corkscrew appearance.Video
- GERD vs Eosinophilic esophagitisGERD: heartburn that responds to PPI; eosinophilic esophagitis: dysphagia and food impaction with over 15 eosinophils per HPF despite PPI.
- Barrett esophagus vs Esophageal adenocarcinomaBarrett esophagus: premalignant intestinal metaplasia with goblet cells; adenocarcinoma: invasive gland-forming cancer through the…
- Esophageal squamous cell carcinoma vs Esophageal adenocarcinomaSquamous is upper/mid irritant-linked keratinizing cancer; adenocarcinoma is distal GERD/Barrett glandular cancer.Video
- Mallory-Weiss tear vs Boerhaave syndromeMallory-Weiss is mucosal bleeding; Boerhaave is transmural rupture with mediastinal air or toxicity.Video
- Plummer-Vinson syndrome vs Zenker diverticulumPlummer-Vinson is iron-deficiency web dysphagia; Zenker is food-trapping pouch with halitosis/regurgitation.
- Sliding hiatal hernia vs Paraesophageal hiatal herniaSliding moves the GE junction up; paraesophageal keeps the junction down while stomach herniates beside it.
- Hirschsprung disease vs Pediatric acute bowel obstruction patternsHirschsprung is aganglionic delayed meconium; intussusception is target-sign telescoping; volvulus is bilious twisting emergency.
- Hypertrophic pyloric stenosis vs Neonatal proximal obstruction patternsPyloric stenosis is weeks-later nonbilious outlet obstruction; duodenal atresia/annular pancreas are neonatal bilious duodenal obstruction…
- Intussusception vs Meckel diverticulumIntussusception is painful telescoping with target sign; Meckel is painless bleeding from ectopic gastric mucosa.
- Necrotizing enterocolitis vs Hirschsprung diseaseNEC is premature inflammatory bowel injury with pneumatosis; Hirschsprung is aganglionic delayed-meconium obstruction.
- Intestinal malrotation vs Midgut volvulusMalrotation: the congenital anatomic setup, often silent; midgut volvulus: the acute twist around the SMA with bilious vomiting and…
- Celiac disease vs Infectious malabsorption patternsCeliac is gluten-autoimmune villous atrophy; tropical sprue is exposure-responsive malabsorption; Whipple is PAS-positive systemic…
- Lactose intolerance vs Celiac diseaseLactose intolerance is dairy-triggered osmotic symptoms with normal mucosa; celiac is gluten-triggered immune villous injury.
- Carcinoid syndrome vs InsulinomaCarcinoid is flushing plus diarrhea and 5-HIAA; insulinoma is fasting neuroglycopenic hypoglycemia with high insulin/C-peptide.
- Diverticulosis vs DiverticulitisDiverticulosis is pockets or painless bleeding; diverticulitis is inflamed pockets with pain, fever, and CT inflammation.Video
- Appendicitis vs Right lower quadrant mimicsAbnormal appendix on imaging: appendicitis; enlarged ileocolic nodes after a viral prodrome: mesenteric adenitis; painless bleeding: Meckel.
- Hereditary unconjugated hyperbilirubinemia vs Hereditary conjugated hyperbilirubinemiaGilbert/Crigler-Najjar are unconjugated conjugation defects; Dubin-Johnson/Rotor are conjugated transport defects.
- Direct hyperbilirubinemia vs Indirect hyperbilirubinemiaDirect bilirubin is water soluble and appears in urine; indirect bilirubin is albumin-bound and does not cause bilirubinuria.
- Hepatocellular carcinoma vs Non-HCC primary liver tumorsHCC is hepatocyte cancer in cirrhosis/HBV/HCV with AFP; cholangiocarcinoma is bile duct cancer with obstructive jaundice; adenoma is…
- Hepatic adenoma vs Focal nodular hyperplasiaAdenoma is hormone-linked and can bleed; FNH is vascular-malformation related with central scar and minimal malignant concern.Video
- Adenomatous colorectal cancer syndromes vs Hamartomatous polyposis syndromesFAP is innumerable APC adenomas; Lynch is MMR cancer with few polyps; Peutz-Jeghers is pigmented hamartomas; juvenile polyposis is…
- Tubular adenoma vs Villous or tubulovillous adenomaTubular is usually pedunculated and lower risk; villous/tubulovillous is sessile, larger, and higher cancer risk.
- Right-sided colon cancer vs Left-sided colon cancerRight-sided cancer hides as iron deficiency anemia; left-sided cancer announces with obstruction, stool caliber change, and visible…