Background: After pelvic malignancy radiation, chronic radiation intestinal injury (CRII) is an unavoidable complication, and bleeding is one of the most common symptoms of CRII. Lower extremity deep venous thrombosis (LE-DVT) is another severe complication.Once hemorrhagic CRII patients suffer from LE-DVT, hemostasis and anticoagulation therapy will be adopted simultaneously, which is a therapeutic paradox, extremely intractable and serious. This study was aimed to investigate prevalence and risk factors for LE-DVT in CRII patients, and explore treatment for hemorrhagic CRII patients with LE-DVTMethods: This is a retrospective study,a total of 608 CRII hospitalized patients from November 2011 to October 2018 after pelvic malignancy radiation in our hospital were included.Univariate and multivariate analysis were conducted to investigate the associated risk factors for LE-DVT in CRII patients. Receiver operating characteristic (ROC) curve analysis was performed to investigate the independent risk factors and determine their clinically valid cut-off points. Furthermore, treatment of hemorrhagic CRII patients with LE-DVT was explored.Results: Of the 608 included CRE patients, there were 94 (15.5%) CRII patients with suspicious symptoms of LE-DVT in the lower limbs, and 32 (5.3%) patients were diagnosed with LE-DVT. Among the CRII patients with LE-DVT, 65.6% (21/32) patients were with bleeding simultaneously, 29 (90.6%) patients were anemic, with 17 (53.1%) patients having moderate anemia and 7 (21.9%) having severe anemia. Multivariate analysis showed recent surgical history (≤6 Months) (OR=0.480, 95% CI: 1.430~9.377, p=0.007) and hemoglobin (Hb) (OR=0.965, 95% CI: 0.945~0.986, p=0.001) significantly associated with development of LE-DVT. ROC curve analysis showed optimal cut-off values of Hb were 82.5 g/L (AUC=0.756, 95% CI: 0.688~0.824, sensitivity=71.9%, specificity=75.5%). After colostomy, obvious bleeding remission was found in 84.6% of hemorrhagic CRII patients with LE-DVT rapidly. And LE-DVT of the patients was obvious improved or disappeared following anticoagulation therapy or with vena cava filter or stent placement.Conclusions: Prevalence of LE-DVT in hospitalized CRII patients was 5.3%. Recent surgical history and lower Hb were independently associated with LE-DVT developing in CRII patients. And colostomy could be a good choice for intractable hemorrhagic CRII patients with LE-DVT.