How deep are the lesions of Crohn's disease?

Lesions in Crohn's disease are characterized by their ability to penetrate the entire thickness of the bowel wall, which is why the correct choice is that they involve full thickness of the mucosa. This fulminant characteristic leads to transmural inflammation, which can affect not just the mucosal layer but also the submucosa, muscularis, and potentially the serosa of the gastrointestinal tract. This deep penetration results in a variety of complications, including strictures, fistulas, and abscesses, as the inflammation can create pathways between different parts of the gastrointestinal tract or even involve adjacent structures, highlighting the severity of Crohn's disease and its impact beyond the superficial layers.

While superficial lesions may characterize other gastrointestinal diseases, Crohn's is distinctly known for its depth of involvement in the bowel wall, which is what sets it apart and complicates its management and treatment.