Symptoms that are mistaken for colon cancer include the symptoms of irritable bowel syndrome, Crohn's disease and diverticulosis, according to Mayo Clinic, WebMD, the American Cancer Society and MedicineNet. They include constipation, diarrhea, a change in the consistency of the stool, persistent cramps, gassiness or other abdominal discomforts. Other symptoms are weakness, fatigue and weight loss that can't be explained.
Irritable bowel syndrome is a chronic but benign condition, says Mayo Clinic. IBS does not cause inflammation in the bowel and does not increase the risk of the patient contracting colon cancer. However, a patient who experiences symptoms of IBS for the first time should see his physician to rule out more serious conditions such as colon cancer.
An inflammatory bowel disease such as Crohn's disease also has symptoms that are mistaken for those of colon cancer, says WebMD. People who suffer from Crohn's disease might have fevers and anemia because of blood in their stool and inflammation of the intestine. They may also have small anal fissures, pain and soreness in the belly.
Diverticulosis occurs when pressure in the colon creates tiny pouches, says MedicineNet. The symptoms include constipation that alternates with diarrhea and pain in the abdomen. Diverticulitis occurs when the pouches become inflamed and leads to bleeding from the rectum, infections and intestinal obstruction.