Creating blow-hole colostomy for decompression could provide a time-saving and efficient surgical procedure for a severely debilitated case with a completely obstructed colorectal cancer. Complications are reported as prolapse, retraction, and paracolostomal abscess. However, complication with an ischemic distal limb has not been reported. We report a case of critical intra-abdominal disease after decompressed colostomy for relieving malignant sigmoid colon obstruction; a potential fatal condition should be alerted. A 76-year-old male visited our emergency department for symptoms related to obstructed sigmoid colon tumor with foul-odor vomitus containing fecal-like materials. An emergent blow-hole colostomy proximal to an obstructed sigmoid lesion was created, and resolution of complete colon obstruction was pursued. Unfortunately, extensive abdominal painful distention with board-like abdomen and sudden onset of high fever with leukocytopenia developed subsequently. Such surgical abdomen rendered a secondary laparotomy with resection of the sigmoid tumor along with an ischemic colon segment located proximally up to the previously created colostomy. Eventually, the patient had an uneventful postoperative hospital stay. In the present article, we have described an emergent condition of sudden onset of distal limb ischemia after blow-hole colostomy and concluded that despite the decompressed colostomy would resolve acute malignant colon obstruction efficiently; impending ischemic bowel may progress with a possible irreversible peritonitis. Any patient, who undergoes a decompressed colostomy without resection of the obstructed lesion, should be monitored with leukocyte count and abdominal condition survey frequently.