The non‐inherited gastrointestinal polyposis syndromes represent a group of rare disorders characterized by the presence of multiple, non‐adenomatous polyps on the gastrointestinal mucosa occurring in unrelated patients. We present here a review of the clinical and histo‐ pathological aspects of the syndromes to include the Cronkhite–Canada syndrome, hyperplastic polyposis and lipomatous polyposis. While infrequently encoun‐ tered, these diseases can have devastating clinical effects that may be aggravated by delays in diagnosis and treatment. Prompt accurate diagnosis and treatment of these uncommon disorders depend on a sound working knowledge of the distinct clinical and pathological features described herein.