What internal organs are located by the lower left side of the back?

The left kidney, small intestine and descending colon are all found at the lower left side of the back, also known as the left lumbar region.

The left lumbar region is one of nine regions of the abdominal cavity, and it contains organs from both the digestive and excretory systems. Both the small intestine and the descending colon are components of the digestive system, and they assist the body in converting food into energy and nutrients for the body. The kidneys are part of the excretory system, which filters the blood and removes toxins from the body as well as regulates fluid and electrolyte balances in the body.