Im a 21 year old female. I've notice blood and mucus in my stool since Saturday. Also, I've been constipated for 2 weeks and have had upper left abdominal pain occasionally. When I do pass stool, the stool is soft. Today I almost passed out while driving and I've been dizzy since then. I drink almost a gallon of water everyday so I know I'm not dehydrated. I went to the doctors on Monday and they just gave me a fiber supplement. The doctor also did a rectal exam and told me I didn't have hemorrhoids or bleeding.