Anatomic Features

Let’s take a tour of the normal colon. The colon is about 5-6 feet long. Its primary purpose is to dehydrate and store the liquid stool that enters it. The colon begins in the right lower abdomen where the small intestine ends. This part of the colon is called the cecum. The ileocecal valve (ICV) at the end of the ileum regulates the flow from the small bowel into the colon. Image 1 shows the typical appearance of the ICV as seen from above. It usually has a puffy, orangish appearance and, at times, it is shaped like your lower lip. Image 2 looks directly at the slit opening of the valve. Image 3 is at the base of the cecum where the appendix is attached. Here you see the inside opening of the long finger-like appendix in the base of the cecum. Finally, Image 4 is a picture of the ileum or small bowel after the endoscope has passed through the ICV. You see that the lining here has a fine feathery appearance. The function of the ileum is different from the colon. In the small intestine nutrients are absorbed through tiny wavy fronds called villi, so you see a speckling of light being reflected back from these villi.