Capecitabine and oxaliplatin (CAPOX) plus bevacizumab (BEV) therapy (CAPOX/BEV) is a standard treatment recommended as the first-line treatment for colorectal cancer recurrence. Recently, sinusoidal obstruction syndrome (SOS) and resulting portal hypertension have been reported as important side effects of oxaliplatin. We herein report a rectal cancer patient who underwent percutaneous transhepatic stoma variceal embolization (PTO) and partial splenic artery embolization (PSE) for stomal variceal bleeding and splenomegaly due to portal hypertension caused by SOS after CAPOX therapy. A 43-year-old man who underwent robot-assisted laparoscopic abdominoperineal resection for advanced lower rectal cancer was started on CAPOX/BEV therapy for early recurrence 1 month after surgery. In the sixth course, splenomegaly rapidly worsened, stomal varices appeared, and the stoma began bleeding. At 5 months after the appearance of stomal varices, the splenomegaly worsened, the frequency of stomal bleeding increased, and PTO was performed. Five months later, PSE was performed for splenomegaly and thrombocytopenia. At 5 months since the PSE, the stoma bleeding has not recurred, and the thrombocytopenia has been corrected. The patient has been able to continue chemotherapy. We suggest that staged treatment by PTO and PSE be considered an important treatment option for stomal varices and splenomegaly associated with SOS.