How do i know that my colon is functioning probably? like it's diseas free. could imbalanced meals or not really eating affect seriously my origins ?

Not to worry.: If you are not losing weight and do not have abdominal pain or blood in the stool then i would assume you colon is functioning normally. Try to get a healthy diet of fruits and vegetables and minimize your fat intake and think should be fine. If you have abdominal pain or blood then you should seek care but otherwise it sounds like the colon is working fine. Diseases of the colon give symptoms.