Squamous metaplasia of the rectum may be the result of chronic inflammatory reaction in and about the rectum. Some of the pathological states which lead to squamous metaplasia of the rectal mucosa are of granulomatous origin due to venereal disease. Lymphopathia venereum is one of the conditions which can cause chronic granulomata.
The incidence of rectal complications in lymphopathia venereum has always been regarded as extremely high, particularly in females. Since the disease has been most common in the Negro race, the reported rectal complications have ordinarily been found in Negro people as well. Presumably in the absence of pederasty, practiced mainly by the male, the disease spreads to the rectum by means of direct spread through the rectovaginal septum and drainage into the perirectal lymphatics with submucosal involvement and subsequently ulceration of the rectal mucosa and ultimate stricture formation. With this chronic inflammatory process, the mucosa may exhibit changes
POLIVY C, ROSENTHAL II. Squamous Metaplasia And Papillomatosis of Rectum. Arch Surg. 1964;89(6):1077-1082. doi:10.1001/archsurg.1964.01320060145026