Im 18 and i have been under alot of stress latley and i have had a change in bowel movements that is my only symptom do i have colon cancer?

Not Likely: Young adults with colon cancer often have known genetic problems or at least a strong family history. These are really rare. See: http://jnci.oxfordjournals.org/content/early/2011/03/24/jnci.djr094.full Stress often causes simple diarrhea or may be implicated in irritable bowel syndrome (IBS). See: http://www.mayoclinic.org/diseases-conditions/irritable-bowel-syndrome/basics/causes/con-20024578

Need more data: What kind of changes in bowel movement have you seen? Is it either diarrhea or constipation? Are the symptoms accompanied with any nauseousness, abdominal pain, acid regurgitation, weight loss, etc? We need more data, such as having tried to relieve your stressful life? Please tell me in more detail of your bowel symptoms. It seems, from what you have, colon cancer is a big jump.

Very unlikely at 18: Start with increasing fiber intake: fruits, vegetables, dried beans, bran cereals. Drink plenty of water 6-8 cups a day, and consider a daily walk or other exercise program. You may be able to normalize your bowel movements. Otherwise you will want to discuss this problem with your doctor who can perform a detailed history and physical. Best wishes.