<unk>  is a<unk><unk>  imaging technique used to evaluate bowel wall features of both upper and lower gastro-intestinal tract, although it is usually used for small bowel evaluation. It is a less invasive technique with the advantages of no ionizing radiation exposure, multiplanarity and high contrast resolution for soft tissue. The term MR<unk>  and MR enteroclysis are similar, but the first is referred to a MR exam with orally administered enteric contrast media, and the second to a more invasive technique in which enteric contrast media is administered through the fluoroscopy-guided positioned nasojejunal tube. The need for imaging assessment of small bowel diseases comes from the limits of traditional endoscopy in evaluating ileum loops, as other modern techniques such as capsule endoscopy are not routinely performed as it is seldom available in most centers. Over the past several years assessment of small bowel diseases was performed by Barium follow through, or upper and lower gastrointestinal series, that provided plan film of bowel loop lumen, thanks to the swallowing or instillation of radiopaque agents mixed with water or other neutral contrast media. Gastrointestinal series allow to depict lumen caliber, gross mucosal alterations and wide fistulous tract, but were poorly diagnostic for submucosal or extraluminal features. CT scan instead provides cross sectional and multiplanar images of intraluminal and extra-mucosal, extra-luminal or even extra-enteric features, but costing higher radiation dose. The spread of MR technique has revolutionized the diagnostic imaging of the small bowel loop, restricting CT scan to particular situations, such as emergency or MR contraindications like patients with pacemaker implant, recently implanted vascular/bilious stent or other ferromagnetic prosthesis/devices. It is a safe, multi-planar imaging modality with high soft tissue contrast resolution that does not expose to ionizing radiation, so it is feasible for young patients or when several follow up are required.
Magnetic resonance enterography
Computed tomography enterography
Double-balloon enteroscopy
EGS 
Fecal fat test
GI cocktail
Stool test
Capsule endoscopy