CGRN Cheat Sheet 2026

The 30 highest-yield CGRN facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. What is capsule endoscopy primarily used to evaluate? → Small bowel pathology including obscure GI bleeding, Crohn's disease, and tumors
2. During EGD, a Forrest Ia bleeding ulcer is identified. What does this classification indicate? → Active spurting arterial hemorrhage
3. A patient with hemochromatosis is found to have a serum ferritin of 2,800 ng/mL and transferrin saturation of 72%. What is the first-line treatment? → Therapeutic phlebotomy weekly until ferritin < 50 ng/mL
4. Which assessment finding would most likely lead to a higher ASA physical status classification? → Severe COPD requiring home oxygen
5. What is the function of the air/water channel in a standard gastroscope? → To provide lens washing (water) and insufflation (air) through the distal tip
6. A patient presents with coffee-ground emesis and hemoglobin of 7.2 g/dL. What is the Blatchford score used for? → Stratifying upper GI bleeding risk pre-endoscopically
7. The classic triad of intussusception in a toddler includes colicky abdominal pain, vomiting, and which other finding? → Currant-jelly stools
8. What is the recommended minimum withdrawal time during a screening colonoscopy? → 6 minutes
9. What is the primary purpose of chromoendoscopy during upper endoscopy? → Enhance detection and characterization of mucosal lesions by highlighting surface patterns
10. What anatomic landmark confirms cecal intubation during colonoscopy? → Appendiceal orifice and triradiate fold
11. What is the mechanism of action of propofol used for endoscopic sedation? → GABA-A receptor potentiation
12. What is the recommended storage method for reprocessed endoscopes to prevent recontamination? → Hung vertically in a ventilated cabinet with valves removed
13. During sedation monitoring, the capnography waveform becomes flat. What does this indicate? → Apnea — the patient has stopped breathing
14. A patient is undergoing an upper endoscopy with biopsy. Which of the following is an absolute contraindication for this procedure? → Suspected bowel perforation
15. A patient reports latex allergy. What accommodations must be made for endoscopy? → Ensure a completely latex-free environment
16. A patient scheduled for endoscopy has a known history of Creutzfeldt-Jakob disease (CJD). What is the recommended approach? → Use a disposable endoscope or quarantine the scope after use
17. Which imaging modality is preferred for initial evaluation of suspected appendicitis in a pediatric patient to minimize radiation exposure? → Ultrasound of the right lower quadrant
18. A patient with ileostomy is at increased risk for which electrolyte disorder? → Sodium and fluid depletion (hyponatremia/dehydration)
19. Which medication is first-line therapy for primary sclerosing cholangitis (PSC) to slow bile duct fibrosis? → No proven disease-modifying therapy currently exists
20. One potentially dangerous consequence of ____ is toxic mega colon. → Ulcerative colitis (UC)
21. During endoscopy, which transmission-based precaution is required for a patient with active pulmonary tuberculosis? → Airborne precautions with N95 respirator
22. Which anatomical structure is responsible for preventing the backflow of bacteria-laden contents from the colon into the small intestine? → Ileocecal valve
23. A patient with primary sclerosing cholangitis undergoes ERCP. What associated condition should the team know about? → Ulcerative colitis
24. Which layer of the GI tract wall contains the submucosal plexus (Meissner's plexus) responsible for regulating secretions? → Submucosa
25. Which nutritional support route is preferred when a patient's GI tract is functional but oral intake is insufficient? → Enteral nutrition via nasogastric tube
26. A patient with autoimmune hepatitis is most likely to have which serologic marker? → Anti-smooth muscle antibody (ASMA)
27. Which of the following should be done if a patient who is scheduled for a colonoscopy has a nose stud and an enclosed lip ring? → Remove both prior to the procedure
28. The vast surface area of the small intestine, critical for nutrient absorption, is primarily achieved through which combination of anatomical features? → Plicae circulares, villi, and microvilli
29. Which type of polyp has the highest malignant potential in the colon? → Villous adenoma
30. Who is credited with developing the first practical flexible fiberoptic gastroscope? → Basil Hirschowitz