Recent studies have suggested a link between GnRH and gastrointestinal function [12, 13], and some patients develop severe dysmotility in the form of chronic intestinal pseudo-obstruction (CIPO) or enteric dysmotility (ED) after treatment with GnRH analogs in relation to in vitro fertilization (IVF) or endometriosis [14]. The gene discussed is GNRH1; the disease is endometriosis.