A case report of a young, healthy female who presented as an emergency with large bowel obstruction secondary to a rectosigmoid tumour. Acute presentation was preceded by a progressive history of change in bowel habit managed medically in the community with laxative treatment. The family history of note included breast cancer of an identical triplet aged 41 years. An emergency Hartman's procedure was successfully performed the same day as presentation due to the high risk of perforation. The patient was discharged home within a week. Histology confirmed adenocarcinoma, Dukes' Stage C and oncologists have now taken over care of the patient. Discussion points explore whether it is appropriate to refer a young healthy patient presenting with a change in bowel habit if she is resistant to medical management in the community and in the absence of other red flag symptoms. The family history of malignancy and genetic associations are also considered.