A genetic disorder causing impairments in the sucrase-isomaltase enzyme, which is responsible for sugar and a large part of starch digestion. There are five subtypes recognized by Orphanet: Congenital sucrase-isomaltase deficiency with starch intolerance, congenital sucrase-isomaltase deficiency without starch intolerance, congenital sucrase-isomaltase deficiency with minimal starch tolerance, congenital sucrase-isomaltase deficiency without sucrose intolerance, and congenital sucrase-isomaltase deficiency with starch and lactose intolerance.