Background: Intraluminal small intestinal obstructions (ISIO) are common in the United Kingdom, but most published studies are from North America. Objectives: To describe ISIO prevalence among all colic cases undergoing laparotomy at an English equine hospital between 2018 and 2024, and to identify risk factors for developing pre-operative and post-operative reflux (POR) and survival. Study design: Retrospective cohort study. Methods: Data on age, breed, gender, heart rate (HR), PCV, total solids concentration (TS), serum lactate and peritoneal lactate concentrations on presentation, development of pre-operative reflux and POR, complications (thrombophlebitis, sepsis, ileus, laminitis, surgical-site infection), duration of hospitalisation and survival to discharge were obtained. Univariable logistic regression was used to investigate the relationship between these parameters and development of POR and survival to discharge. Results: Thirty-three patients met the inclusion criteria. ISIO prevalence was 7.2% (95%CIs:5.2%-9.8%). At presentation mean HR was 55bpm (36-96bpm), PCV was 37% (28-52%), TS was 69g/L (52-86g/L), serum lactate concentration was 2.6mmol/L (0.5-15.7mmol/L) and abdominal lactate concentration was 6mmol/L (0.7-22.3mmol/L). Nasogastric reflux on presentation was seen in 5/33 patients, 9/33 developed POR and 25/33 survived to discharge. Mean hospitalisation time was 10 days (3-38 days). For each 10 units of increase in HR above 45bpm, the odds of developing POR increased 2.05-fold (p=0.025; 95%CIs:0.99-4.26). Horses that survived were significantly less likely to have developed POR than non-survivors (p<0.001; OR:0.03; 95%CIs:0.003-0.22) or post-operative complications (p<0.001; OR:0.04; 95%CIs:0.004-0.405). Main limitations: retrospective, single-centre design. Conclusions: ISIO prevalence in England aligns with North America. High HR on admission is related to POR and development of POR is associated with reduced survival.