Barium Meal Study (Old/Obsolete Test)

What it showed for different ulcers:

• The duodenal cap (the bulb-shaped beginning of the small intestine) looks deformed/distorted on X-ray.
• If complications develop (called secondary diverticulum - a small pouch bulging out), the shape looks like a 3-leaf clover - this is called trifoliate deformity.

• On the inner curve of the stomach: the ulcer crater creates a small pocket or dent that sticks outward - called a "niche" (like a hole in a wall).
• On the outer curve of the stomach: the muscles around the ulcer go into spasm (contract), pulling the wall inward and creating a visible notch on the opposite side.

Benign (non-cancerous) vs. Malignant (cancerous) ulcers:

Tests for H. pylori

INVASIVE TESTS (require endoscopy + biopsy)

• A biopsy piece is placed in a urea solution
• H. pylori produces an enzyme called urease, which breaks down urea and turns the solution pink/red
• Fast result (within minutes to hours)
• High specificity (very accurate when positive)
• False negatives can occur if patient is on PPIs or antibiotics

• Biopsy sample is stained (H&E stain) and examined under microscope
• You can directly see the bacteria
• Sensitive and specific
• Gold standard for diagnosis

• Biopsy is grown in the lab under special low-oxygen (microaerophilic) conditions
• Growth is slow and difficult
• Used mainly when antibiotic resistance testing is needed (e.g. recurrent infection after treatment)

NON-INVASIVE TESTS (no endoscopy needed)

• Patient drinks a solution containing labelled carbon (C-13 or C-14)
• If H. pylori is present, its urease breaks down the urea, releasing labelled CO₂ in the breath
• Breath is collected and analysed
• Very accurate for both diagnosis AND confirming cure
• Wait at least 6-8 weeks after treatment before testing to avoid false negatives
• Avoid PPIs/antibiotics before the test

• A stool sample is tested for H. pylori proteins (antigens)
• Accurate, non-invasive, cheap
• Good for both initial diagnosis AND test of cure
• Should use only locally validated tests

• Detects IgG antibodies against H. pylori in blood
• Simple and cheap
• Cannot confirm eradication - antibodies stay in the blood for months to years even after the bacteria is gone
• Less useful in areas with low H. pylori prevalence

Quick Summary Table

Investigations in Gastric Ulcer (Surgical Perspective)

1. UPPER GI ENDOSCOPY (OGD) - Most Important

• Directly visualizes the ulcer - its size, location, appearance, edges
• Tells you if it looks benign or malignant (suspicious features: irregular, heaped-up, raised edges)
• Allows you to take biopsies (tissue samples) to rule out cancer
• Can also be therapeutic - to stop bleeding or dilate obstruction

• Every gastric ulcer MUST be biopsied (unlike duodenal ulcer, which is rarely malignant)
• Take biopsies from all 4 quadrants of the ulcer edge
• 1 biopsy = 70% sensitivity for cancer
• 4 biopsies = 95% sensitivity
• 7 biopsies = 98% sensitivity
• Also take biopsy for H. pylori (rapid urease test / histology)

Key rule: A gastric ulcer is treated as cancer until proven otherwise by biopsy.

2. BARIUM MEAL X-RAY (Now Mostly Replaced)

• Patient drinks barium contrast, X-rays taken
• Benign ulcer appears as a "niche" (outpouching crater) on the lesser curvature
• Double-contrast technique detects 80-90% of ulcers; single contrast misses 50%
• Cannot take biopsy - that's its big limitation
• Still useful when endoscopy is not available or contraindicated

3. TESTS FOR H. PYLORI

4. ROUTINE BLOOD TESTS

• Complete Blood Count (CBC) - check for anaemia (from chronic bleeding)
• Blood group and crossmatch - in case surgery is needed
• Serum electrolytes, urea, creatinine - especially if vomiting/obstruction
• Coagulation profile (PT/INR) - pre-op assessment
• Liver function tests - baseline
• Blood glucose - pre-op

5. CT SCAN / CT ANGIOGRAPHY

• If malignancy is suspected - CT chest/abdomen/pelvis for staging
• CT angiography - if there is acute upper GI bleeding that is not controlled by endoscopy; helps identify the bleeding vessel
• Endoscopic ultrasound (EUS) - for depth of ulcer penetration and lymph node assessment if cancer is suspected

6. FOLLOW-UP ENDOSCOPY (Very Important in Surgery)

• Repeat OGD at 6-8 weeks after starting treatment
• To confirm ulcer has healed
• If not healed - take repeat biopsies (cancer can be missed on first look)
• If biopsy is benign but ulcer not healing after 3 months - surgical resection may be needed

Summary Flowchart (Simple)

Gastric Ulcer suspected
        ↓
Upper GI Endoscopy (OGD) ← Investigation of Choice
        ↓
Biopsy from all 4 quadrants (rule out cancer)
        +
Biopsy for H. pylori (RUT)
        ↓
Benign → Medical treatment (PPI + H. pylori eradication)
        ↓
Repeat OGD at 6-8 weeks
        ↓
Not healing → Surgery
        
Malignant → CT staging → Surgery (gastrectomy)