The man in the article was diagnosed with a Gastrointestinal disease that eventually made it so that they had to remove his intestines. The surgery made it so that when he digests his food the waste no longer comes out of his anus because his intestines have been removed. His waste is emptied into the bag that you see. If you remove the bag you would see what is called a stoma. It is the stub of the intestines that were removed. There are many diseases that could lead to one needing a colostomy bag. Sometimes its the whole intestines and sometimes its just a portion of the intestines that gets rerouted.