Gastroparesis & Dumping Syndrome

(Gastroenterology 2004;127:1589-91 & 1592-1622. Neurogastroenterol Motil 2006;18:263-83)

GASTROPARESIS

Definition:

Motility disorder of the stomach, often associated with other intestinal motility disorders; Results from impairment of normal gastric emptying
Factors of gastric motility and emptying:
- Composition of the meal: liquids/solids empty at different rates, content influence (i.e. fat empties slow)
- Neuroregulators: Neural innervation is complex but largely involves the vagus (innervates stomach to right colon)
- Hormonal regulators: Motilin/Neurotensin accelerate, Secretin/cholecystokinin delay gastric emptying
- Gastric pacemaker: on greater curve of stomach, oscillates at 3 cycles/min

Etiologies:

Idiopathic: most common cause; May be sudden or insidious development of symptoms; ? viral association
Gastrointestinal:
- Paraneoplastic: gastric cancer, pancreatic cancer, metastatic disease: breast, small cell lung
- Atrophic gastritis (Type A): most commonly with solid food delayed emptying
- Chronic intestinal pseudoobstruction
- Radiation-induced: any abdominal radiation
- Anorexia nervosa, Obesity
Endocrine:
- Diabetic: Well established; Gastroparesis does not necessarily correlate with symptoms; some asymptomatic patients have abnormal GES
- Hypo/Hyperthyroidism, Hypoparathyroidism
Surgical:
- Post-op complications: Vagotomy, Roux-en-Y gastrojejunostomy, Fundoplication, Gastric bypass, Esophagectomy, etc
Rheumatological
- Scleroderma, polymyositis, dermatomyositis, SLE
Infectious disorders:
- Chagas’ disease (Trypanosoma Cruzi), VZV, CMV, EBV, Clostridium Botulinum, HIV
Neurologic:
- Porphyria, Brainstem tumor, Parkinson’s disease, Multiple sclerosis, Spinal cord injury, Heavy-metal poisoning
Other:
- Stress from pain or anxiety
- Myotonic dystrophy, Muscular dystrophy, Amyloid, Idiopathic constipation

Drugs that *delay* gastric emptying:
Alcohol	Aluminum antacids	Anticholinergics	Atropine	Beta agonists
Calcitonin	CCB	Diphenhydramine	Glucagon	IL-1
L-dopa	Lithium	Ondansetron	Opiates	PPIs
Phenothiazine	Progesterone	Sulcrafate	Tobacco	TCAs
Drugs that *accelerate* gastric emptying:
BB	Cisapride	Diazepam	Domperidone	Erythromycin
H2s	Metoclopramide	Naloxone	PG-E