A parastomal hernia is an incisional hernia in relation to an intestinal stoma on the abdominal wall and a common complication after stoma formation. Most parastomal hernias are relatively asymptomatic, but sometimes, a loop of bowel may become trapped in the sac, resulting in obstruction or strangulation. We reported a case with a para-colostomy hernia causing small bowel obstruction in a 45-years-old female who had had a transverse loop colostomy for severe rectovaginal fistula 2 years before due to recurrent cervix cancer. The patient required resection of gangrenous portions of small bowel and large bowel. A review of the preventative information of parastomal hernia and management is discussed. A parastomal hernia shonld be considered as a cause of small bowel obstruction in anyone who has a stoma. Early detection and repair of the strangulated hernia are recommended.