To observe the clinical efficacy and safety of Shenling Baizhu Powder（参苓白术散）combined with methalazine in the treatment of ulcerative colitis with spleen deficiency and dampness syndrome.

A total of 82 ulcerative colitis patients with spleen deficiency and dampness syndrome admitted from March 2021 to March 2024 were divided into groups by random number table method. According to different treatment methods, the patients were divided into the methalazine group treated solely with methalazine and the combined TCM group treated with Shenling Baizhu Powder combined with methalazine, with 41 cases in each group. The therapeutic effect, the symptom remission time（mucous, pus and blood stools, abdominal pain and diarrhea）, the changes of TCM syndrome scores such as mucous, pus and blood stools, loose stool diarrhea, abdominal distension, abdominal pain and fatigue before and after treatment, as well as the improved Mayo SCore（Mayo）and disease activity index（DAI）were observed in two groups. The changes in DAI scores, tumor necrosis factor-α（TNF-α）, interleukin-8（IL-8）and interleukin-17（IL-17）, and the quality of life of the two groups were assessed by inflammatory bowel disease quality of life questionnaire（IBDQ）, and the adverse reactions were compared between the two groups.

The total effective rate of the combined TCM group was significantly higher than that of the mesalazine group, and the symptom remission time（mucous, pus and blood stools, abdominal pain and diarrhea）was shorter than that of the mesalazine group（P < 0.05）. The TCM syndrome scores such as mucous, pus and blood stools, loose stool diarrhea, abdominal distension, abdominal pain and fatigue of the two groups before treatment were not significant（P > 0.05）. After treatment, the scores of TCM symptoms such as mucus, abscess, blood stool, loose stool diarrhea, abdominal distension, abdominal pain and fatigue, Mayo and DAI scores, the levels of TNF-α, IL-8 and IL-17, and IBDQ scores were improved in two groups. And these scores and levels in combined Chinese medicine group were better than those in mesalazine group（P < 0.05）. The adverse reaction rate of the combined TCM group was lower than that of the mesalazine group（P < 0.05）.

The combination of Shenling Baizhu Powder and methalazine in the treatment of ulcerative colitis with spleen deficiency and dampness has a good effect, and the clinical symptoms and quality of life of the patients have been significantly improved after treatment, which can better promote the recovery of the patients, and the treatment is safe and reliable.