Abstract
Four cases of anal beleding which were similar to the early phase of ulcerative colitis were described as acute hemorrhagic colitis. Several hours or days after admini-stration of antihistaminics or antibiotics against common cold, four young adults were admitted to our hospital complaining of watery diarrhoea followed by severe anal bleeding similar to ulcerative colitis. Occult blood was positive, however, no pathogenic bacteria or viruses were detected in their stool. White blood cell counts showed within normal limits and no specific abnormal findings were detected in their liver function test, immunological studies and so on. Endoscopic examination by magnifying colonoscope type CF-MB-M (Olympus) were carried out within several hours after the onset of anal bleeding and revealed mul-tiple hemorrhagic spotts, edema and congestion on the surface of the mucosa in the so-called "left colon". Normal vascular pattern was completely disturbed, however, remarkable ulceration, friability of the mucosa and mucopurulent exudate which were commonly seen in ulcerative colitis were not inspected endoscopically. These findings were similar to stage I of acute phase (early stage) of ulcerative colitis which was describec by Roth. Histological studies by biopsy specimens showed marked congestion, vascularity and edema of the mucosa, however, infiltration of inflammatory cells and erosion were not so remarkable. No crypt abscesses were detected. These histological findings revealed non-specific inflammtory pattern of the colon. Symptom of anal bleeding cured easily without any therapy within one or two days and the mucosal inflam-mation was also confirmed to subside endoscopically. No recurrence of symptoms occured during our follow up observation from eight months to three years. Concerning to the pathogenesis of this disease, no remarkable factors could be demonstrated in our series. It is not clear whether symptom of common cold is one of the symptoms of this disease or only allergic reaction by the administration of drugs causes the inflammation in the left colon. According to these clinical, enidoscopical and histological points of view, acute hemorrhagic colitis seems to be similar to the early stage of ulcerative colitis in some features. Several clinical points of acute hemorrhagic colitis, however, such as easy healing without any therapy and no recurrence of symptoms are quite different from ulcerative colitis. Therefore, the pathogenesis of acute hemorrhagic colitis is suspected to be different from those of ulcerative colitis and considered strongly to be a new entity inflammatory colon disease. Moreover, it is emphasized that more additional documentation of this disease should be neces-sary to resolve the pathogenesis or to differentiate from other inflammatory colon disease.
