It can identify the cause of a lung, liver, or pancreas disease because there is an arc reflex existing between the colon, the collarette, and one particular organ (See the illustrations in my book on pages 182-209).
I have often observed in the iris of patients with lung cancer or severe respiratory disorder, a connected extension of the colon tissue and a distension of the collarette over the lung area. This shows the implication of the colon and the nervous system thus need to be treated as well.
A zigzagging collarette pointing to organs such as the pancreas, liver, or spleen may indicate a negative effect on their function. Emotional behavior, also has a negative effect on spleen, liver, gall-bladder, and thyroid, which has been observed in the iris.
Figure 5: Inter-relationship between the colon and the organs of the endoderm layer