Consider the following medical report that includes the patient's historical health records. Use it to predict the disease that the patient is high likely exposed to. 

 Medical Report: history of present illness: this is a 74-year-old gentleman with a history of multiple gastrointestinal bleeds all of unclear source but all self-resolved. first episode was 12 years ago when the patient developed rectal bleeding. multiple suspects including diverticulosis, gastric polyp, internal hemorrhoids and gastric ulcer. positive gastroesophageal reflux disease and hiatal hernia. the patient took dextra for the fifth time for knee pain and on he had lower gastrointestinal bleed. admitted to and source was unclear. the patient had negative esophagogastroduodenoscopy, negative colonoscopy except for diverticulosis and internal hemorrhoids. on he had frank hematochezia with three bowel movements, had lightheadedness. he went to the emergency room, no chest pain, no shortness of breath, no nausea or vomiting. he did have some positive lower abdominal pain during bowel movement which was revealed after having bowel movement. in emergency department the patient's hematocrit was 32.5 and stable. he had one liter of ivf and mesenteric angiography which was negative. he was orthostatic by heart rate. he was admitted to the micu. in the micu the patient's hematocrit was 25. he was transfused two units packed red blood cells, hematocrit then stabilized. the patient had q 4 to 6 hours hematocrit monitoring. in the micu he did have melanotic stool but hematocrit remained stable and was then transferred to the medicine floor for further management. past medical history: diverticulosis, internal hemorrhoids, multiple gastrointestinal bleeds that self-resolved, gastric polyp and shallow gastric ulcer, gastroesophageal reflux disease, hiatal hernia, hypertension, status post transurethral resection of prostate, status post bilateral inguinal hernia repair, hypercholesterolemia, hyperhomocystinemia. anemia found to be iron deficiency anemia. medication: 1. prilosec. 2. vasotec. 3. iron sulfate. 4. colace 5. vitamin b12. 6. niacin. 7. folate. 8. dextra. allergies: ampicillin and gentamicin which cause rash. family history: father had cancer, no inflammatory bowel disease history, no bleeding disorder. social history: etoh occasionally. no tobacco, he quit in the 70's. he is retired and lives with wife. physical examination: temperature 97.5, pulse 84, blood pressure 152/80, respirations 18, sating at 96% on room air. generally he is in no acute distress, pleasant, sitting in chair . head, eyes, ears, nose and throat: extraocular movements intact, pupils are equal, round, and reactive to light and accommodation, no jugular venous distention. supple neck and moist mucous membranes. heart is regular rate and rhythm. normal s1 and s2. no murmurs. lungs are clear to auscultation bilaterally. no wheezes or crackles. abdomen is soft, nontender, nondistended with good bowel sounds. the patient is 1+ lower extremity edema. 2+ dorsalis pedis. neurologic: cranial nerves 2 to 12 are intact. strength is and symmetric. toes are downgoing. white count 6.5, hematocrit 29.4, platelet count 247. sodium 139, potassium 3.4, chloride 108, bicarbonate 25, platelet count 9, creatinine 1.2. glucose is 93. inr 1.1, ptt is 24.5. prothrombin time is 12.7. ck and troponins have remained within normal limits and the patient has ruled out for myocardial infarction. during his transfer to the medicine service the patient had continued blood per rectum times 3 or 4 times. he had a repeat esophagogastroduodenoscopy which was negative. surgery was consulted on the patient and felt that one option included a heparin induced bleeding in order to appreciate the source of the bleeding. this was planned however, the patient's bleeding spontaneously resolved and hence patient was not taken to the operating room for heparin induced bleeding. additionally given that he had no further episodes of bleeding it was decided to just watch and see if the patient had any other events. the patient then did have some blood per rectum and a tagged red blood cell scan was performed on however, this did not reveal the source of bleeding either so again it is felt that perhaps a heparin induced bleeding scan was the best course of action for this patient however, as stated above the bleeding then spontaneously resolved and the patient had no further episode of bright red blood per rectum and he had a stable hematocrit. hence it was decided that the patient would be discharged home for further follow-up with his primary care physician and that further workup could be considered as an outpatient should the patient have significant blood per rectum. medications on discharge: 1. prilosec 20 mg p.o. q day. 2. colace. 3. vitamin b12. 4. folic acid. 5. niacin. the patient was to follow-up with his primary care physician within one weeks time and was to report sooner should he have any further episodes of bright red blood per rectum. , m.d. dictated by: medquist36 procedure: other endoscopy of small intestine diagnoses: unspecified essential hypertension acute posthemorrhagic anemia diaphragmatic hernia without mention of obstruction or gangrene right bundle branch block hemorrhage of gastrointestinal tract, unspecified diverticulosis of colon (without mention of hemorrhage) internal hemorrhoids without mention of complication benign neoplasm of stomach 

Answer: The patient is high likely exposed to