Internal View of Lumbar Region
Thanks to the thick, protective mesentery and sheer mass of the intestines (not to mention the consequences if they’re damaged), many surgeries of the pelvic and lumbar organs are performed by opening the back, instead of the abdomen.
You can clearly see both the ascending and descending colon and the kidneys in this dissection.
Anatomy, Descriptive and Surgical. Henry Gray, 1911.