This patient in his 80s was transferred for suspected intestinal obstruction. Sigmoid volvulus was diagnozed by "coffee-bean sign" in abdominal X-ray and obstruction of the sigmoid colon with whirl sign in contrast-enhanced CT. Endoscopic detorsion was attempted but was in vain due to strong torsion and poor blood flow. Symptoms were temporarily relieved with endoscopic degassing. Three days later, abdominal distention recurred. The following colonoscopy showed worsened torsion and exposure of muscular layer, implicating impending perforation. Poor general condition made surgical intervention too risky. Insertion of a transanal ileus tube for decompression was considered, but the hard and thick tip made it impossible to be passed through the site of impending perforation. Instead, we placed a urinary ballooned (Foley) catheter and successfully decompressed. Symptoms were fully relieved without perforation during the course.