Angiectasia is one of the diseases that should be considered in lower gastrointestinal haemorrhaging in elderly people. This article details our experience with a case of rectal angiectasia with myelodysplastic syndrome (hereafter referred to as MDS) as the underlying disease, where the identification of the source of haemorrhaging and diagnosis were difficult. The patient was an 81 year-old male diagnosed with MDS. The patient was diagnosed with sigmoid colon diverticulitis on the basis of left lower abdominal pain and the appearance of melena. As the melena continued even after signs of swelling improved, a colonoscopy was conducted. Oozing from the angiectasia was detected immediately above the dentate line and stopped with APC. Although it is believed that colonic angiectasia usually occurs on the right side of the abdomen, we concluded that it is important to thoroughly examine the recto-anal area as well.
