The hindgut is the posterior (caudal) part of the alimentary canal. In mammals, it includes the distal third of the transverse colon

Transverse colon

The transverse colon, the longest and most movable part of the colon, passes with a downward convexity from the right hypochondrium region across the abdomen, opposite the confines of the epigastric and umbilical zones, into the left hypochondrium region, where it curves sharply on itself beneath...

 and the splenic flexure

Splenic flexure

The splenic flexure is a sharp bend between the transverse and the descending colon in the left upper quadrant of humans. The left colic flexure is near the spleen, and hence called the splenic flexure. There are two colic flexures in the transverse colon — the other being the hepatic...

, the descending colon

Descending colon

The descending colon of humans passes downward through the left hypochondrium and lumbar regions, along the lateral border of the left kidney....

, sigmoid colon

Sigmoid colon

The sigmoid colon is the part of the large intestine that is closest to the rectum and anus. It forms a loop that averages about 40 cm...

 and rectum

Rectum

The rectum is the final straight portion of the large intestine in some mammals, and the gut in others, terminating in the anus. The human rectum is about 12 cm long...

.

Blood flow

Arterial supply is by the Inferior mesenteric artery

Inferior mesenteric artery

In human anatomy, the inferior mesenteric artery, often abbreviated as IMA, supplies the large intestine from the left colic flexure to the upper part of the rectum, which includes the descending colon, the sigmoid colon, and part of the rectum...

, and venous drainage is to the portal venous system

Portal venous system

In human anatomy, the hepatic portal system is the system of veins comprising the hepatic portal vein and its tributaries. It is also called the portal venous system, although it is not the only example of a portal venous system, and splanchnic veins, which is not synonymous with hepatic portal...

. Lymphatic drainage is to the chyle cistern.

Autonomic innervation

The hindgut is innervated via the inferior mesenteric plexus

Inferior mesenteric plexus

The inferior mesenteric plexus is derived chiefly from the aortic plexus.It surrounds the inferior mesenteric artery, and divides into a number of secondary plexuses, which are distributed to all the parts supplied by the artery, viz., the left colic and sigmoid plexuses, which supply the...

. Sympathetic innervation is from the Lumbar splanchnic nerves

Lumbar splanchnic nerves

The lumbar splanchnic nerves are splanchnic nerves that arise from the lumbar part of the sympathetic trunk and travel to an adjacent plexus near the aorta...

(L1-L2), parasympathetic innervation is from S2-S4.