The developmental process, independent of morphogenetic (shape) change, that is required for a columna/cuboidal epithelial cell of the intestine to attain its fully functional state. A columnar/cuboidal epithelial cell of the intestine mature as they migrate from the intestinal crypt to the villus. [ http://www.ncbi.nlm.nih.gov/pubmed/18824147 GOC:dph ]