It's obvious that reversing the other axes of the body, where is the back and belly, or the mouth and the anus, would have some serious evolutionary consequences.
Unlike its cousin, ulcerative colitis, which only affects the large intestine, Crohn disease causes inflammation and tissue destruction anywhere along the gastrointestinal tract, from the mouth to the anus.
According to these texts, witches practiced rituals including kissing the Devil's anus and poisoning or bewitching targets the devil singled out for harm.
Now if we zoom into a cross-section of the rest of the gastrointestinal tract, anywhere from the esophagus till the anus, the walls are typically lined by the same four layers of tissue.
In fact, the enteric nervous system, which is an extensive mesh-like network of neurons that controls your entire digestive tract from the esophagus to the anus, doesn't even require the brain at all.
Anatomically, the digestive system consists of a 30-foot long, mucous membrane-lined tube beginning with the mouth, where food enters the body, and ending with the anus, where solid waste is excreted.