Gastric Heterotopia in the Rectum: A Rare Cause of Rectal Bleeding

The most commonly presenting symptoms are painless rectal bleeding, tenesmus, rectal or perineal ulceration, anal or abdominal pain, or incidentally discovered on colonoscopy.24 It may be associated with congenital anomalies such as rectal duplication and other system abnormalities, including vertebral, digital, and other heterotopia.2,3 The endoscopic appearance used to be a polypoid mass; it has also been described as ulcers, diverticula, reddish mucosal plaques, fold, or flaps.4 Heterotopic gastric mucosa may develop at all levels and in all quadrants of the rectum.4 The most reported type of gastric mucosa is fundic or gastric body type followed by a mixture of gastric mucosa.4 There is only one case reported of pure pyloric type, which was associated with malignancy.2 The presence of H. pylori has been noted in some patients with rectal gastric heterotopic mucosa.3 Determination of the rectal pH may be helpful for the diagnosis, with a value of less than 4 being indicative of gastric heterotopy. Ultrasonography is useful for demonstrating the solid nature of the lesion and the nuclear MRI and the CT scan are helpful to assess the extension of the illness. 99m-technetium-pernechnetate scanning may provide further information, showing increased uptake in the heterotopic tissue of the rectum, which is best observed on a lateral view to prevent obstruction by the bladder.