One of the latest strategies proposed in IBD pharmacotherapy is using neprilysin (NEP) inhibitors to protect the endogenous opioids, enkephalins (Met- and Leu-enkephalin)—which participate in antinociception [7], the regulation of GI motility [7], the modulation of the immune system [8,9], affecting anti-inflammatory, hormonal, and behavioral responses [10]—against fast degradation and loss of activity. This evidence concerns the gene MME and inflammatory bowel disease.