Major Causes of Gastroparesis

Gastroparesis is most often caused by

• diabetes
  
  
• postviral syndromes
  
  
• anorexia nervosa
  
  
• surgery on the stomach or vagus nerve
  
  
• medications, particularly anticholinergics and narcotics (drugs that slow contractions in the intestine)
  
  
• gastroesophageal reflux disease (rarely)
  
  
• smooth muscle disorders such as amyloidosis and scleroderma
  
  
• nervous system diseases, including abdominal migraine and Parkinson's disease
  
  
• metabolic disorders, including hypothyroidism

source: http://digestive.niddk.nih.gov/ddiseases/pubs/gastroparesis/index.htm