LC-MS	Liquid Chromatography–Mass Spectrometry
NMR	Nuclear Magnetic Resonance
NOESY	Nuclear Overhauser Effect Spectroscopy
CPMG	Carr-Purcell-Meiboom-Gill
UAP	Upper Abdominal Pain
DAIP	Diffuse Abdominal/Intestinal Pain
HMDB	Human Metabolome Database
LV	Latent Variable
OPLS-DA	Orthogonal Partial Least Square–Discriminant Analysis
MVDA	Multivariate Discriminant Analysis
VIP	Variable Importance in Projection
PCA	Principal Component Analysis
PE	Phosphatidylethanolamine
PC	Phosphatidylcholine