Large intestine or colon has an important role in human digestion system including assimilation process, especially vitamin, mineral, and water, forming feces from leftovers food that has not function to body. Human life style including the type of food that consumed is affect to colon condition. Iridology as science used to knowing organs condition by iris can be alternative to early examination colon condition. The examination can be used in computerization with applying Principal Component Analysis (PCA) as feature extraction method and Support Vector Machine (SVM) as classification method in data input iris image.