Business Insider When symptoms begin to surface with colon cancer, they can be mistaken for symptoms of other digestive issues, such as IBS or celiac disease. If a colonoscopy isn’t suggested by a physician, some, such as the patients in this article, may not find out they have cancer until it's in the later stages. Najeeb Al Hallak, M.D., MS , medical oncologist and co-leader of the Gastrointestinal and Neuroendocrine Oncology Multidisciplinary Team at Karmanos, advised to always get ...