A case of acute hemorrhagic rectal ulcer (AHRU) after surgery for squamous cell carcinoma of the buccal mucosa

A 65-year-old man visited our hospital on November 8, 2000 because of pain in the right cheek mucosa. He had diabetes mellitus and hypertension and was a carrier of hepatitis B virus. After excision of the tumor, right conservative neck dissection and microvascular reconstruction with a free rectus abdominis muscle flap, he received ventilatory assistance for 3 days. He was given antibiotics and nonsteroidal anti-inflammatory drugs (NSAIDs) for postoperative pneumonia and a wound infection. On 17th postoperative day, the hemoglobin level suddenly decreased from 9.5g/dl to 8.0g/dl over the course of 2 days. Gastrointestinal examination showed no bleeding points. A new episode of massive bleeding occurred on the 21st day. The bleeding point could not be identified by colonoscopicexamination, radioisotope angiography, or angiography of the artery. However, a wide shallow ulcer of the rectum was finally found 2cm from the anal verge on another colonoscopic examination on the 28th day. The AHRU in this patient might have been caused by postoperative stress, a large dose of NSAIDs, underlying disease, or a combination of these factors.