Objective <p>To evaluate the clinical efficacy of umbilical herbal application combined with pestle needle therapy in the treatment of functional diarrhea (FD) due to deficient cold of the spleen and stomach.</p> Methods <p>A total of 72 patients with FD were enrolled and randomly assigned to two groups using the random number table method, with 36 patients in each group. Both groups received conventional Western medication treatment. The observation group additionally received umbilical application of Wen Yang Bu Pi Gao (Yang-warming and spleen-strengthening herbal paste) combined with pestle needle therapy. After 7 d of treatment, the clinical efficacy was assessed. Traditional Chinese medicine (TCM) symptom scores, irritable bowel syndrome-quality of life (IBS-QOL) score, and the incidence of adverse reactions were compared between the two groups.</p> Results <p>The total effective rate in the observation group was 91.7%, which was significantly higher than 69.4% in the control group (<i>P</i>&lt;0.05). After treatment, TCM symptom and IBS-QOL scores in both groups were significantly reduced compared to those before treatment (<i>P</i>&lt;0.05), and the scores in the observation group were significantly lower than those in the control group (<i>P</i>&lt;0.05). No adverse reactions occurred in either group during the treatment period.</p> Conclusion <p>Compared to conventional Western medication treatment alone, the addition of umbilical application of Wen Yang Bu Pi Gao combined with pestle needle therapy can more effectively alleviate clinical symptoms and improve the quality of life in patients with FD due to deficient cold of the spleen and stomach.</p>