Absorptive function of the mucosa of intestine can be best assessed by -
D-xylose absorption test is a medical test performed to diagnose conditions that present with malabsorption of the proximal small intestine due to defects in the integrity of the gastrointestinal mucosa. D-xylose is a monosaccharide, or simple sugar, that does not require enzymes for digestion prior to absorption Ref Davidson edition23rd pg809
d-Xylose test
NET- PABA test
Stool fat estimation
Urobilin levels
G.I.T