Gastroduodenal Disorders: H. pylori, Peptic Ulcer Disease and Gastric Neoplasia
This domain tests practical decision-making: how to test for and eradicate Helicobacter pylori, how to risk-stratify and treat peptic ulcers, and how gastric cancer risk is stratified endoscopically and histologically.
Helicobacter pylori
- Use urea breath test or stool antigen. Hold PPI for 2 weeks and antibiotics for 4 weeks before testing; serology cannot confirm active infection or eradication.
- In Egypt and other areas with high clarithromycin resistance, first-line therapy is bismuth quadruple for 14 days: PPI, bismuth, tetracycline and metronidazole. Clarithromycin triple therapy is reserved for proven low-resistance settings.
- Confirm eradication at least 4 weeks after antibiotics with urea breath test or stool antigen.
- Gastric MALT lymphoma: eradication is first-line for localized H. pylori-positive disease; t(11;18) translocation predicts failure and need for radiotherapy or chemotherapy.
Peptic ulcer disease and bleeding
- Main causes are H. pylori, NSAIDs including low-dose aspirin, and rarely Zollinger-Ellison syndrome.
- Forrest classification: Ia spurting, Ib oozing, IIa visible vessel, IIb adherent clot, IIc flat pigmented spot, III clean base. Forrest Ia-IIb need combination endoscopic therapy plus high-dose PPI (80 mg bolus, then 8 mg/hour for 72 hours). IIc and III do not need endoscopic therapy.
- Continue or restart aspirin for secondary cardiovascular prevention after hemostasis following multidisciplinary discussion.
Gastric neoplasia
- Intestinal-type cancer follows the Correa cascade: H. pylori gastritis, atrophic gastritis, intestinal metaplasia, dysplasia, carcinoma. OLGA and OLGIM staging stratify risk and surveillance.
- Diffuse-type cancer is associated with CDH1 mutation; hereditary diffuse gastric cancer justifies prophylactic total gastrectomy.
- Early gastric cancer that is mucosal, differentiated, 2 cm or less and ulcer-negative can be cured by endoscopic submucosal dissection.
Worked example
A 55-year-old presents with melena. Endoscopy shows a 1 cm duodenal ulcer with a nonbleeding visible vessel (Forrest IIa). Correct care is epinephrine injection plus thermal or mechanical therapy, high-dose PPI infusion for 72 hours, H. pylori testing once stable, and repeat endoscopy only for rebleeding.
Traps
- Using IgG serology to confirm eradication.
- Testing for H. pylori while the patient takes a PPI.
- Applying endoscopic therapy to a clean-based ulcer.
- Forgetting that NSAID ulcers may be H. pylori negative yet still need PPI maintenance if NSAIDs continue.