&NA;Analysis of the 27 cases of heterotopic gastric mucosa reported in the literature and a new case described here elucidates the main features of this disease: 1) all but one asymptomatic case were diagnosed in infants or in adults under 26 years old; 2) although rectal bleeding occurred in 24 patients, rectal peptic ulceration was found in only 13; 3) six of the patients also had rectal duplication; and 4) 19 times the limited extension of the heterotopic gastric mucosa was compatible with a complete excision by a transanal approach.