Background: Bowel and mesenteric injuries have high morbidity and mortality rates in the trauma group due to non-specific symptoms and are often obscured in the context of multiple traumas, contributing to an increased risk of peritonitis and sepsis. The purpose of this research was to assess the diagnostic accuracy of 16-slice multidetector computed tomography (MDCT) findings in the diagnosis of bowel and mesenteric injuries accompanied by the association of these findings with the treatment strategy. Methods: A retrospective study was performed on 86 blunt-abdominal-trauma patients, hospitalized at the emergency department of our institution from June 2018 to July 2019 (75 men and 11 women aged 4–76 years old with a median age of 40.88), who had 16-slice MDCT diagnosis of blunt bowel and mesenteric injuries and were treated by nonsurgical and surgical treatment. Ethical clearance was taken from the institute ethics committee with waiver of consent. Results: The specificity of bowel-wall rupture, active extravasation, and reduced bowel-wall enhancement were 100%, 98.15%, and 100%, respectively. Pneumoperitoneum had the highest sensitivity of 83.33%. Bowel-wall rupture, Janus signs, pneumoperitoneum, and mesenteric stranding were significantly correlated with surgical results. The existence of these results improved the likelihood of 7-, 6-, 29- and 3-fold surgical treatment, respectively. Inter-observer consensus was very strong for bowel-wall rupture, active extravasation, bowel hematoma, and pneumoperitoneum. Conclusion: Bowel-wall rupture was the definite sign of bowel injury and its connection with surgical treatment was important. Pneumoperitoneum was not a specific indication of blunt bowel injury; but when this is detected, emergency intervention should be suggested.