I'm really worried about colon cancer as in the last week my constipation got really bad and i couldn't go and even though i had the need and when i finally did there was bright red in the stool not the water and it was all in smaller parts?

Very rare chance: Colon cancer is quite rare in teenagers except in those with familial history of Familial Adenomatous Polyposis. You are very likely to have experienced a rectal bleeding associated with constipation which can easily be ameliorated by bowel softeners.

Hemorrhoids, constip: I understand your Anxiety. At age 19 with only symptom of constipation, you do not have Colon cancer. Bright red color in stool can be due to Hemorrhoids. Please see a Surgeon for Diagnosis and Treatment. Your Health is Precious!

So rare: You are more likely to get hit by a bus today than have colon cancer at your age. The " blood" you refer to, is almost definitely a rectal fissure or hemorrhoid. Most colon cancers have no symptoms. If you are having abdominal pains, fullness, nausea, etc - then you should see doctor as there are literally hundreds of conditions other than cancer that could cause symptoms in abdomen.