Autologous Platelet-rich Plasma (PRP) and Thrombin Coagulum for the Topical Treatment of Rectal Mucosal Ulcers

10 mL PRP and thrombin coagulum gel was administered every night for seven consecutive days by the same IBD specialist. Before the intervention, the patients had to defecate. The prepared PRP gel was injected into the external opening of the rectum using the same syringe, and the patient was kept in the Trendelenburg position to ensure that the therapeutic drug remained in place under gravity. The normal supine position was returned after 15 minutes to minimize PRP leakage. The outflow was observed, and the amount of outflow was recorded.

10 mL PPP and thrombin coagulum gel was administered every night for seven consecutive days by the same IBD specialist. Before the intervention, the patients had to defecate. The prepared PPP gel was injected into the external opening of the rectum using the same syringe, and the patient was kept in the Trendelenburg position to ensure that the therapeutic drug remained in place under gravity. The normal supine position was returned after 15 minutes to minimize PPP leakage. The outflow was observed, and the amount of outflow was recorded.

For patients receiving mesalazine suppositories, the intervention was inserted through the anus with a disposable sanitary finger to the point of slight loss of resistance. To facilitate intervention, moisturize with water or cream. If the drug drains within 10 minutes, it should be re-inserted. The swelling at the local injection site on each group's intervention day was recorded.

Patients, in every arm, all receive infliximab (300 mg iv at 0, 2, 6 weeks, and then every eight weeks).