How long can colon cancer go untreated once u first have symptoms of it...like partial obstruction and pain?

Varies: It depends on the location of the cancer. Cancers on the right side cause anemia before causing obstruction. Cancers on the right side are more likely to cause obstruction. Either of these symptoms is not an early sign. It also depends on the biologic characteristic of the tumor. For good health - Have a diet rich in fresh vegetables, fruits, whole grains, milk and milk products, nuts, beans, legumes, lentils and small amounts of lean meats. Avoid saturated fats. Drink enough water daily, so that your urine is mostly colorless. Exercise at least 150 minutes/week and increase the intensity of exercise gradually. Do not use tobacco, alcohol, weed or street drugs in any form. Practice safe sex, if you have sex.