GNRH2 and diabetes mellitus: IgM antibodies against GnRH1, progonadoliberin-2, and GnRH receptors may occur in a subgroup of patients with functional bowel disorders and dysmotility, both in idiopathic forms and when associated with diabetes mellitus, posterior laryngitis, primary Sjögren’s syndrome, or GnRH treatment (39, 40, 42–45).