Squamous cell metaplasia of colorectal epithelium is very rare. There have been only 29 cases previously reported in the English language medical literature. The cause and consequences of squamous cell metaplasia in the colorectum are unknown. We encountered a patient with squamous cell metaplasia in rectum who have had a curious history for more than 20 years. This case may be useful in attempting to understand the pathogenesis of squamous cell metaplasia in colorectum.
