There seems to be some continual confusion about the differences between Irritable Bowel Syndrome & Inflammatory Bowel Diseases.
The main difference between the two is that Irritable Bowels Syndrome is a functional disorder, meaning there is little to no physical evidence of the disorder besides it’s symptoms. Inflammatory Bowel Diseases are not functional disorders and are diagnosable based off of physical evidence. Irritable Bowel Syndrome is usually much less severe than Inflammatory Bowel Diseases. Additionally “Inflammatory Bowel Disease” is not the actual name of a disease, but a classification for bowel diseases of an inflammatory nature. The two main Inflammatory Bowel Diseases are Ulcerative Colitis & Crohn’s Disease. They are not the same thing, though they have similar symptoms & treatments.
I made this handy chart below so people can get a better idea of the differences.