What is the difference between gastritis and gastroenteritis in terms of diagnosis and management?

Gastritis vs. Gastroenteritis: Key Differences

Gastritis is chronic inflammation of the stomach lining requiring endoscopic diagnosis and histologic confirmation, while gastroenteritis is acute inflammation of both stomach and intestines caused by infectious agents that presents with self-limited diarrhea and vomiting.

Anatomic Location and Pathophysiology

Gastritis:

• Affects only the stomach mucosa 1
• Represents chronic inflammatory changes with potential for glandular atrophy and metaplasia 1
• Develops over months to years, not acutely 2

Gastroenteritis:

• Involves both stomach and intestines (or colon in colitis) 3
• Represents acute infectious inflammation 3, 4
• Develops over hours to days 4

Etiology

Gastritis:

• H. pylori infection is the dominant cause of chronic gastritis 1
• Autoimmune mechanisms causing corpus-predominant atrophic gastritis 1, 5
• Not caused by acute viral or bacterial infections 2, 6

Gastroenteritis:

• Viruses are most common (rotavirus, norovirus, adenovirus) 3, 7
• Bacteria second most common (including C. difficile) 3, 4
• Parasites less common 3
• Transmitted via fecal-oral route and contact 7

Clinical Presentation

Gastritis:

• Often asymptomatic or causes chronic dyspepsia 8
• No acute diarrhea 2
• May present with iron or B12 deficiency as first manifestation 1
• Associated with increased gastric cancer risk in advanced cases 1

Gastroenteritis:

• Acute onset of nausea, vomiting, diarrhea, and abdominal pain 3, 4
• Typically non-bloody diarrhea with viral causes 7
• Symptoms resolve within one week in most cases 3
• Dehydration is primary concern 4
• Can lead to post-infectious IBS in 9% of cases 3

Diagnostic Approach

Gastritis:

• Requires endoscopy with visualization of pale mucosa, visible vasculature, and loss of gastric folds 1
• Histologic confirmation mandatory with topographical biopsies from body and antrum in separate jars 1
• Test for H. pylori using non-invasive methods (urea breath test, stool antigen) 8
• Check antiparietal cell and anti-intrinsic factor antibodies if autoimmune gastritis suspected 1

Gastroenteritis:

• No testing needed for mild symptoms resolving within one week 3
• Multiplex antimicrobial testing preferred for severe or prolonged symptoms, bloody stool, or recent antibiotic use 3
• Stool cultures no longer first-line 3
• Test for C. difficile if recent antibiotic exposure 3

Management

Gastritis:

• Bismuth quadruple therapy for 14 days to eradicate H. pylori (bismuth 120mg QID + two antibiotics + high-dose PPI) 8
• High-potency PPI (esomeprazole 20-40mg BID, rabeprazole 20mg BID, or lansoprazole 30mg BID) for 4-8 weeks 8
• Confirm eradication 4-6 weeks after completing antibiotics using non-serological testing 8, 5
• Screen and treat iron and B12 deficiencies, especially in corpus-predominant disease 1, 5
• Endoscopic surveillance every 3 years for advanced atrophic gastritis 1
• Screen for autoimmune thyroid disease in autoimmune gastritis 1, 5

Gastroenteritis:

• Oral rehydration for mild-moderate symptoms 3, 4
• Nasogastric or IV hydration for severe dehydration 3
• Antiemetic, antimotility, or antisecretory drugs for symptom control 3
• Antimicrobials only for: C. difficile, travel-related diarrhea, severe bacterial infections, or parasitic infections 3
• Most cases self-resolve without antibiotics 3, 4

Critical Pitfalls to Avoid

For Gastritis:

• Do not diagnose gastritis without histologic confirmation 1, 2
• Do not use 7-day antibiotic regimens—must be 14 days 8
• Do not fail to obtain separate antral and corpus biopsies in labeled jars 8, 5
• Do not rely on symptom resolution without confirming H. pylori eradication 8

For Gastroenteritis:

• Do not order stool cultures as first-line testing 3
• Do not routinely prescribe antibiotics for viral gastroenteritis 3
• Do not miss C. difficile testing in patients with recent antibiotic exposure 3

Long-term Sequelae

Gastritis:

• Progression to intestinal metaplasia, dysplasia, and gastric adenocarcinoma 1
• Type 1 gastric neuroendocrine tumors in autoimmune gastritis 1, 5
• Pernicious anemia as late manifestation 1, 5

Gastroenteritis:

• Post-infectious IBS develops in 9% of patients, accounting for >50% of all IBS cases 3
• Post-infectious lactose intolerance 3