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)
-Treat underlying disorders (systemic d/o, eating d/o, psychiatric d/o)
-Surgery (last resort - pyloroplasty or gastrojujenostomy)