To begin, position the rat on its back in dorsal recumbency on an anatomical bench. Cover the surgical site with sterile gauze soaked in bacteriostatic saline. After creating a six-centimeter midline incision, reveal the peritoneal surface using a retractor.
Then, cut the terminal jejunum. Position the cecal stump one to two centimeters from the ileocecal valve and then cut it. Isolate the blood supply to the terminal jejunum and tie it off with an 8-0 suture thread.
Now, begin the resection of the right hemicolon, carefully tying off the right hemicolon and middle colic vein. Next, separate the inferior mesenteric artery and isolate the inferior rectal artery. Proceed to isolate down the rectum until reaching two centimeters from the anal verge.
Then, cut the distal rectum at an angle of approximately 45 degrees to prevent postoperative narrowing. Then, fold the terminal ileum into a J shape to create a pouch for the ileum. Using an interlocking stitch, perform posterior wall anastomosis and enhance the anterior wall with a modified Connell stitch.
Ensure there is no torsion in the mesentery. At intervals, suture the anterior side walls of the pouch's opening and the lateral wall of the rectal stump using an 8-0 suturing thread for traction. Then, apply a full layer continuous lock suture to both the anterior and posterior walls.
Sequentially close the abdominal muscle fascia and skin using 4-0 sutures. To treat the rat ileal pouchitis model with DSS, dissolve four grams of DSS in 100 milliliters of pure water, freshly prepared daily. Administer pure water to the IPAA group and 4%DSS to the pouchitis group from postoperative day 31 to day 35.
Initially, both the IPAA and ileal pouchitis groups had equal body weights and were generally in good condition. By the 35th day after surgery, the weight of the ileal pouchitis group was significantly lower than that of the IPAA group.
