Gastroparesis
Gastroparesis is delayed gastric emptying without mechanical obstruction, caused by impaired gastric motility.
Etiology
- Diabetes mellitus (most common; due to autonomic neuropathy).
- Post- surgical (e.g., vagotomy, gastric surgery).
- Neurological disorders (Parkinson’s disease, multiple sclerosis).
- Medications (opioids, anticholinergics).
- Idiopathic.
Pathogenesis
- Damage to vagal nerve or enteric nervous system → impaired coordination of gastric contractions.
- Reduced antral motility → decreased grinding and propulsion of gastric contents.
- Delayed emptying → food retention in stomach.
Clinical manifestations
- Early satiety.
- Nausea, vomiting (often of undigested food).
- Bloating, abdominal discomfort.
- Weight loss (due to poor oral intake).
- Erratic glucose control in diabetics.
Gastritis
Definition
Gastritis is inflammation of the gastric mucosa, which can be acute or chronic.
Etiology
Acute gastritis
- Nonsteroidal anti- inflammatory drugs (NSAIDs).
- Alcohol.
- Stress (severe illness, burns → "Curling ulcers").
- Chemotherapy.
- Bile reflux.
Chronic gastritis
- Helicobacter pylori infection (most common).
- Autoimmune gastritis (anti- parietal cell antibodies).
- Chronic bile reflux.
- Long- term NSAID use.
Pathogenesis
Acute gastritis
- Direct mucosal injury by NSAIDs (inhibit prostaglandin synthesis), alcohol, or bile → reduced protective mucus and bicarbonate.
- Acid-mediated mucosal damage → erosion, hemorrhage.
Chronic gastritis
- H. pylori gastritis: Bacterial toxins and local inflammation → damage to antral mucosa → increased gastrin → increased acid → further injury.
- Autoimmune gastritis: Antibodies against parietal cells → loss of acid and intrinsic factor → achlorhydria and vitamin B12 deficiency → pernicious anemia.