Congenital tufting enteropathy (CTE) is a rare inherited intractable diarrhea of infancy characterized by villous atrophy and absence of inflammation, with intestinal epithelial cell dysplasia manifesting as focal epithelial tufts in the duodenum and jejunum. CTE presents in the first few months of life with chronic watery diarrhea and failure to thrive, and most affected individuals require parenteral nutrition for normal growth and development (summary by Sivagnanam et al., 2008). Semiquantitative assessment of the epithelial surface in CTE patients revealed that 80 to 90% contained tufts, compared to only 16% in patients with celiac disease and less than 10% in normal jejunum (Reifen et al., 1994). For a discussion of genetic heterogeneity of diarrhea, see DIAR1 (214700).