What Causes Sharp Abdominal Pain With Dark, Tarry Stools?

67yo male who lives in an assisted living facility. Seen today in clinic: CC (chief complaint) is sharp abdominal pain. Ht: 5’9 ½ “, wt: 201 lbs., frame: large. Nutrition related labs: Hgb 9mg/dl, glucose 115mg/dl, chol 205mg/dl, trig 133mg/dl. Reports dark (tarry) bowel movements. Currently does not follow any diet restrictions.