A 37-year-old female patient with no prior colonoscopy and without chronic medical conditions undergoes an urgent laparotomy for a high-grade large bowel obstruction. At surgery, an obstructing rectosigmoid mass is discovered, with significant distention of the colon proximal to the mass. The cecum demonstrates significant distention with several partial-thickness serosal tears secondary to overdistention. The patient’s vital signs are stable, the patient’s small intestine and rectum are not distended, and there is no gross contamination. The best surgical option is