Crohn's colitis is an inflammatory bowel disease affecting the colon, which can result in serious complications such as intestinal perforation and peritonitis. Clinically, it presents with symptoms like abdominal pain, diarrhea, and vomiting, which can be misinterpreted or overlooked, leading to diagnostic delays. We present an autopsy case of a 43-year-old woman with no significant past medical history, who initially consulted the Emergency Department for persistent abdominal pain, vomiting, and diarrhea over a 10-day period. Despite symptomatic treatment, no further diagnostic investigations were conducted. Three days later, she presented a sudden loss of consciousness at home and she was declared dead shortly thereafter. A medico-legal autopsy was ordered to determine the cause of death. External examination revealed cyanosis of the face and nails, abdominal distension, and no signs of trauma. At the internal examination, there were a stercoral peritoneal effusion of approximately 400 ml and multiple perforations in the colon, specifically in the ascending colon and sigmoid regions. Further examination showed an inflamed, hemorrhagic colonic mucosa. Histological analysis revealed deep ulcerations and areas of transmural inflammation alternating with healthy mucosa, typical of Crohn's colitis. No other organ abnormalities were noted. Toxicology tests were negative. The cause of death was attributed to peritonitis secondary to colonic perforation due to undiagnosed Crohn's colitis.