Crohns and Colitis Foundation.com. IBS is a syndrome. IBD is a disease. Drs like to use them with each other. But they are not the same. And yes most IBDs are immune system diseases. You have to look farther for more info than Wiki. I am not going to injest parasites. Check into what hookworms and roundworms do. And once you get them,you must be treated for a very long time with poison.
Treatment for hookworms involves taking one pill on one occasion. They're only a health concern if the parasite load is extreme. For minor infections, usually there are no symptoms and common guideline in that case is no treatment is necessary. In small numbers they're basically harmless, yet at the same time are being used by some to treat various illnesses. I don't know anything about roundworms though.