Objective: To evaluate the clinical efficacy of Xiaochengqi Decoction enema in the treatment of acute simple intestinal obstruction and to compare its effects with those of Gastrografin and soap water enema. Methods: This study was designed as a prospective randomized controlled study. A total of 150 patients diagnosed with acute simple intestinal obstruction and admitted to the Emergency Department of Linfen People’s Hospital between September 2023 and August 2025 were enrolled. Patients were randomly assigned into the Xiaochengqi Decoction group, the Gastrografin group, and the soap water group, with 50 patients in each group. All groups received conventional conservative management, including fasting, continuous gastrointestinal decompression, fluid resuscitation, and correction of water–electrolyte and acid–base imbalances. In addition, patients in the Xiaochengqi Decoction group received modified Xiaochengqi Decoction retention enema, those in the Gastrografin group received 76% Gastrografin via nasogastric tube, and those in the soap water group received soap water enema. Clinical efficacy, symptom relief time, length of hospital stays, and imaging improvement were compared among the three groups. Results: No statistically significant differences were observed among the three groups in baseline characteristics (p > 0.05). Overall clinical efficacy differed significantly among the groups (χ² = 11.429, p = 0.003). The total effective rate was highest in the Xiaochengqi Decoction group (90.0%), followed by the Gastrografin group (86.0%) and the soap water group (76.0%). Significant differences were also identified in abdominal pain relief time, time to first flatus, time to first defecation, and length of hospital stay (all p < 0.001), with the shortest durations observed in the Xiaochengqi Decoction group. Imaging improvement rates differed significantly among groups (χ² = 13.333, p = 0.001), with the highest rate in the Xiaochengqi Decoction group (98.0%). Conclusion: Xiaochengqi Decoction enema, when combined with conventional conservative therapy, may improve clinical outcomes in patients with acute simple intestinal obstruction, promote recovery of bowel function, and reduce hospital stay, demonstrating favorable clinical applicability.