Water-assisted colonoscopy in inflammatory bowel diseases: From technical implications to diagnostic and therapeutic potentials

Figure 4 Advantages of water-aided colonoscopy in colonic mucosal lesion resections. A: In the water-aided technique (upper portion of the figure), the introduction of water into the colon lumen allows for de-tensioning of the colonic walls and elevation of the mucosa (in pink) and submucosa (in yellow); B: This facilitates the removal of the mucosal lesion, as in an endoscopic mucosal resection using a snare; C: Conversely, in the gas-aided technique (lower portion of the figure), this elevating effect is absent, and the tension of the colonic walls is increased, resulting in reduced thickness of the mucosa and submucosa; D and E: Consequently, the submucosa must be elevated by injecting substances (e.g., diluted adrenaline in saline solution (D), to enable mucosal resection (E).