Editing Intestinal Segments and Urinary Diversion (section)

=== Colon ===
* The large bowel is divided into the:
*# Cecum
*# Ascending colon
*# Transverse colon
*# Descending colon
*# Sigmoid colon
*# Rectum
* '''The ascending colon''' is fixed to the right posterior abdominal wall to '''the level of the hepatic flexure, at which point the hepatocolic ligament secures this portion of the colon to the liver.'''
* '''The transverse colon''' lies free within the abdominal cavity and '''is fixed in the left upper quadrant at the splenic flexure by the phrenocolic ligament.''' '''The transverse colon is attached to the stomach by the gastrocolic omentum.'''
** '''Omentum flap should be based off of blood supply from the right gastroepiploic artery'''
*** The right and left gastroepiploic arteries supply the greater curvature and the omentum.
*** The pedicle can be based on either the right or left gastroepiploic artery; however, the caliber of the right gastroepiploic artery is usually larger, thus favoring its use.
* The descending colon is fixed to the left lateral abdominal wall
* The sigmoid colon may or may not lie free within the abdominal cavity
* '''Arterial blood supply'''
** '''The colon receives its blood supply from the superior mesenteric artery, inferior mesenteric artery, and internal iliac arteries'''. The major arteries supplying the colon and rectum include the ileocolic, right colic, middle colic, left colic, sigmoid, superior hemorrhoidal, middle hemorrhoidal, and inferior hemorrhoidal arteries.
** INSERT FIGURE
** '''Weak points involving the vascular supply to the colon (3):'''
**# '''Between the junction of the sigmoid and superior hemorrhoidal (Sudeck critical point)''' '''arteries'''
**# '''Midpoints between the middle colic and right colic arteries'''
**# '''Midpoint between the middle colic and left colic arteries''' (not shown in above diagram, but left colic artery is first branch of IMA (also not shown) and supplies the marginal artery§)
*** '''Although anastomoses in these areas usually heal well, provided the principles of proper technique are followed, it is recommended to select an area for the anastomosis to one side of these points'''
* '''Venous drainage'''
** '''The inferior mesenteric vein drains into splenic vein.'''
** '''The superior mesenteric vien combines with the splenic vein to form the hepatic portal vein'''
** INSERT FIGURE