Though diabetes is the most common identifiable cause for gastroparesis, most cases are idiopathic!

Other frequent causes of gastroparesis include post-surgical (i.e. vagal nerve injury), post-viral (lasting ~ a year), medications, neurologic disorders, and autoimmune (i.e. paraneoplastic).

Toolbox of therapies for gastroparesis:
  -Metoclopramide (first line prokinetic therapy; <1% risk of tardive dyskinesia)
  -Erythromycin (tachyphylaxis with oral use after a few weeks)
  -Doperidone (not FDA approved, approved in Canada, like metoclopramide but w/o CNS effects)
  -TCAs (help with nausea/vomiting, but does not increase gastric emptying - in fact, may worsen it)
  -Botox injections to the GE junction
  -Gastric Electrical Stimulation (for compassionate treatment for refractory symptoms)
  -Diet modification
  -Treat underlying disorders (systemic d/o, eating d/o, psychiatric d/o)
  -Surgery (last resort - pyloroplasty or gastrojujenostomy)