Objective To investigate the efficacy of Saccharomyces boulardii combined with ursodeoxycholic acid in the treating rectal ulcerative colitis (UC) and its influence on intestinal mucosal barrier function.

Methods A total of 88 patients with rectal UC were randomly divided into observation group and control group, with 44 cases in each group. The scores of main symptoms (abdominal pain, diarrhea, purulent stool), score of the Inflammatory Bowel Disease Questionnaire (IBDQ), levels of inflammatory factor indicators interleukin-6 (IL-6), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α) and levels of intestinal mucosal barrier function indicators the ratio of urinary lactolic acid to mannitol (L/M), serum D-lactic acid (D-LA), serum diamine oxidase (DAO), and serum lipopolysaccharide (LPS) were compared between the two groups before and after treatment. The incidence of adverse reactions were compared between two groups.

Results After treatment, the scores of abdominal pain, diarrhea and purulent stool in both groups were significantly lower than those before treatment, while the IBDQ score was significantly higher than that before treatment, and the scores of abdominal pain, diarrhea and purulent stool in the observation group were significantly lower than those in the control group, while the IBDQ score was significantly higher than that in the control group (P < 0.05). After treatment, the levels of serum D-LA, DAO, LPS and urinary L/M in both groups reduced significantly, and the levels of these indicators in the observation group were significantly lower than those in the control group (P < 0.05). After treatment, the levels of serum IL-6, TNF-α and IL-1β in both groups reduced significantly, and the levels of these indicators in the observation group were significantly lower than those in the control group (P < 0.05). The total effective rate inthe observation group was 86.36%, which was significantly higher than 68.18% in the control group (P < 0.05). There were no significant differences in incidence rates of adverse reactions such as lower abdominal pain, allergies and refractory constipation between two groups (P>0.05).

Conclusion Saccharomyces boulardii combined with ursodeoxycholic acid is effective in the treatment of patients with rectal UC, which can effectively improve symptoms such as abdominal pain, diarrhea and purulent stool, inhibit the inflammatory response of the body, and alleviate damage to the intestinal mucosal barrier.