Endometriosis is a disease that causes endometrial tissues to proliferate outside of the uterus. The condition is often attributed to estrogen imbalance and can lead to severe inflammation and bleeding, where it is believed that 10% of female patients experience this illness. Endometrial growth can occur in the ovaries, fallopian tubes, stomach, and gastrointestinal tract. Twelve percent of endometriosis cases can be seen in the intestines, with the rectosigmoid colon accounting for 72% of these cases. Patients with intestinal endometriosis may present with moderate symptoms, such as constipation, but they may experience more serious complications as well such as intestinal bleeding. Although the presence of endometrial tissue in the colon is already a rare phenomenon, it is even rarer for endometrial growth to perforate the entire mucosa of the sigmoid colon. A study in 2010 reported that only 21 of such cases have occurred since 1931. The patient in this case report had a gene (MUTYH) mutation that put her at risk for colorectal cancer, and she was ultimately treated with segmental resection of the sigmoid colon. The final pathology of the specimen revealed that the patient’s lesion was endometrial growth. In this case report, we present a rare finding of endometrial tissue perforating through a patient’s intestinal lumen, which was successfully treated with surgical intervention.