Endoscopic Evaluation of Colonic Inflammation

Mice were anesthetized with 4% isoflurane prior to endoscopy. Colonoscopy was performed on the 7th day of post DSS treatment and inflammation was evaluated by a previously validated endoscopic scoring system (33 (link)), which incorporates 4 different parameters to assess colonic inflammation: perianal findings (diarrhea, bloody feces or rectal prolapse), wall transparency (ability to observe colonic mucosal blood vessels), intestinal bleeding (spontaneous or procedurally induced by endoscope due to mucosal friability), and focal lesions (edema, erosions and ulcers). Colonoscopy was performed as described in Di Martino et al. (34 (link)) using a flexible digital ureteroscope (URF-V, Olympus America, Center Valley, PA) with an 8.5 Fr (2.8 mm) tapered-tip design and a motion range of 180° in an up angle and 275° in a down angle. The endoscope system includes a video system center (Olympus America), a xenon light source (Olympus America) and a video recorder (Medi Capture, Plymouth Meeting, PA). Sub scores for each parameter ranging from 0 (normal colonoscopy) to 3 (maximum severity of colonic changes) were used to evaluate colonic inflammation. The sum of these sub scores was used to define colonic health as follows: healthy (0–1), mild colitis (2–4), and moderate colitis (5–7).