Acute hemorrhagic rectal ulcer syndrome: the first case series from Thailand.

The term "Acute hemorrhagic rectal ulcer syndrome (AHRUS)" has been denoted as a pathological entity that consists of lower gastrointestinal bleeding with unique clinical features. The common setting can be found in elderly patients who were hospitalized with multiple comorbidities. The typical location is around the dentate line. The predominant feature of these ulcers is profuse and painless rectal bleeding. Currently, this condition has not been established worldwide and it has never been reported in Thailand. The authors reported nine cases of AHRUS. These cases were reviewed from the records of endoscopic procedures which were performed at Siriraj Endoscopy Center between September-December 2006. All underwent complete colonoscopy to evaluate endoscopic appearances. Histopathologic findings were thoroughly reviewed. The characteristics of the ulcers are multiple, round or oval shape located just above the dentate line, with/without evidence of bleeding stigmata. Histopathologic features included superficial necrosis, erosions with acute inflammatory cell infiltration and evidence of recent hemorrhage, all of which were confined to the mucosal layer. No organisms were discovered from the lesions. In conclusion, this is the first review of AHRUS which is an uncommon cause of hematochezia in Thailand. Although this clinical entity is not well established in Western countries, the rising incidence of AHRUS in Asia warrants further investigation into its pathogenesis, treatment and prevention.