"Strictly speaking, microscopic colitis (with its two subtypes lymphocytic and collagenous) also belongs to the list. Characterised by chronic diarrhoea with normal radiologic and endoscopic findings and typical findings on histologic examination of colonic tissue and as such a medical differential diagnosis, they will not be covered here.For specifics regarding the above listed dominating entities please refer to their separate articles. Other than sharing a common lack of understanding as to their underlying aetiologies, they are separate entities with little overlap."