This study aimed to explore the efficacy of systematic nursing combined with Lianzhi Xiaoyan capsule on clinical efficacy and the incidence of adverse reactions due to emergency intravenous infusion in patients with acute gastroenteritis. The patients were divided into a control group, comprising patients who received conventional Western medicine treatment and routine emergency nursing, and an observation group, comprising patients who received conventional Western medicine treatment and routine emergency nursing combined with Lianzhi Xiaoyan capsules. The total effective rates among patients in the observation group were higher than those among patients in the control group (P < 0.05). The durations of fever, abdominal pain, diarrhea, nausea, and vomiting among patients in the observation group were shorter than those among patients in the control group. High-sensitivity C-reactive protein, interleukin-6, and CD8+ levels among patients in the observation group were lower than those among patients in the control group. The incidences of adverse reactions during intravenous infusion were lower, and patient satisfaction with nursing care was higher among patients in the observation group than among those in the control group. Systematic nursing combined with Lianzhi Xiaoyan capsules has significant clinical efficacy and can reduce emergency intravenous infusion-related adverse reactions in patients with acute gastroenteritis.