This paper presents a case of necrosis of the pulled-through colon after abdomino-anal resection of the rectum, which was diagnosed by using magnetic resonance imaging (MRI). A 47-year-old man underwent laparoscopically assisted abdomino-anal resection of the rectum with reconstruction of a coloplasty pouch and a transverse colostomy in the course of combination treatment for locally advanced rectal cancer. The postoperative period was complicated by the development of an inflammatory response syndrome. On postoperative day 3 (POD), contrast-enhanced MRI revealed swelling of the 15 cm segment of pulled-through colon up to the coloanal anastomosis with sharply attenuated contrast enhancement, rectoscopy showed no changes. On POD 6, MRI scan revealed a defect in the anterior wall of the coloplasty pouch with a parietal aerocele, rectoscopy showed signs of necrosis of the bowel wall. On POD 10, the MRI scan showed no changes. Due to increasing signs of inflammation, relaparotomy with anastomosis disconnection and resection of the necrotized bowel segment was performed. Ischemia of the pulled-through colon after rectal surgery is a rare but very serious complication. Our clinical case report demonstrates the potential of contrast-enhanced MRI as a non-invasive method in the case follow-up in patients with a complicated postoperative period for early diagnosis of ischemia and bowel wall defects, which helps to make the right patient management plan.