Background: Malignant Bowel Obstruction (MBO) is one of the most common and devastating complications in women with gynecological cancer (GC). There is currently no consensus guideline to improve patient (pt) care in this setting. MAMBO (NCT03260647) is an ongoing prospective study evaluating the clinical implementation of a novel management algorithm for multidisciplinary management of MBO in GC pts. We report preliminary patient outcomes. Methods: All GC pts at Princess Margaret Cancer Centre with a confirmed diagnosis of or are at risk of MBO are eligible for enrollment. Participants follow a low fiber diet titrated by severity of symptom and their monthly weight and albumin levels are recorded, along with standardized patient-reported outcome measures (PROMs) at different time points. For pts who develop MBO, inpatient and ambulatory management algorithms are applied using a multidisciplinary and interprofessional care model consisting of nurses, surgeons, oncologists, radiologists, nutritionists, total parenteral nutrition team, social work, and palliative care. Decisions regarding most optimal management strategies are made by this team with regular MAMBO rounds. A retrospective analysis of pts hospitalized with MBO between 2012 and 2017 was performed in order to have a historical comparison for outcome and survival analysis using Kaplan Meier methods. Results: Since August 2017, 70 pts have been enrolled in MAMBO. Most had high-grade serous ovarian carcinoma (75%), of whom 68% are platinum-resistant. So far, 36 (51%) developed MBO, 6 of whom had multiple sequential episodes. Mean number of days in hospital with MBO was 10 days (median 7, range 0-45), compared to 18 days (median 9, range 0-134) for historical control (p = 0.009). There was no significant loss in weight 6 months from MBO diagnosis but a significant reduction in albumin level by 2.75 g/L after 3 months (p = 0.005). PROMs suggest fatigue and general lack of wellbeing were the symptoms with highest distress. Most patients (78%) received chemotherapy following MBO and most received weekly paclitaxel (36%). Median time from first MBO to death was 219 days (95% CI: 101-not reached) for all-comers in MAMBO and 174 days (95% CI: 98-363) for MBO requiring hospitalization, compared to 108 days (95% CI: 79-160) for historical controls (p = 0.007 and p = 0.062, respectively). Conclusions: Patient care and outcomes from MBO seem to be improved in GC pts enrolled in MAMBO compared to historical controls. Clinical trial information: NCT03260647