Having Diarrhea,vomiting. Found Blood In Stool Due To Internal Hemorrhoids Chances Of Colon Cancer?

My husband went to the doctor 2 days ago for vomitting and diarrea and was told he has a stomach bug. Since then, he has had a lot of blood in stools and blood even ran down his leg from his rectum as he was standing in the kitchen cooking tonight. Earlier today, he had a white stool. He has a history of blood in his stools. he had a colonoscopy approx 5 years ago when he was told the blood was from stress & internal hemerroids. The problem seemed to get better for a while, but he has been in Honduras for the past 2 years where he has been under A LOT of stress. He has had a lot of problems with vomitting and diarrea and blood in his stools from time to time. The doctors always tell him it is a stomach bug and that the blood is from stress. He had a blood panel done earlier this year where they checked his organs and everything was fine. He is worried because his grandfather died from colon cancer and his aunt died from a bad liver . With the current situation - could the bleeding possibly be caused by the diarrea aggravating the hemmoroids? He cannot get to a hospital until tomorrow morning.