Rectal bleeding once in a while with some digestive issues. What could it be?

I am a 22 year old male with no serious health complication so far. I have had bowel movement issues, I feel that I can't empty my bowels completely sometimes. But other times the bowel movements are fine. When I get a sense of incomplete bowel movement, I get dry mouth, itch around the anal area and a sense of dehydration. But when I stock up on fiber and get a bowel movement proper, everything becomes fine. Sometimes, about once in three months when I strain too much to get my stools out, I notice one or two droplets of fresh blood in the toilet bowl. It goes off if my bowel movement become proper the next day. But recently, the last 3 weeks I have had a heartburn issue. The past one month I have not been eating properly due to some work. I went to see a doctor regarding the heartburn, she prescribed me medicine for 3 days and asked me to come back if it doesnt get better. The thing is it is much better now, the burning has stopped, I can swallow properly now but there is still a slight feeling of obstruction in the chest. Yesterday I didn't have a proper bowel movement and noticed blood stains on my stool. Today I had a good proper bowel movement and still noticed 3 droplets of blood on the stool. My stools are not thin, they are not dark/tarry. I don't have any stomach ache, no bloating, no gastric problem. Just on and off bowel issues and a heartburn lately. What could it all be? I have been seen by a psychologist for anxiety issues. With this, I am freaking out even more. Can someone help me out from this?

[Morecambe]

So that yyou are better informed, I suggest you google rectal bleeding and click on to one of the many sites.  The Medicinenet site is particularly informative.

You should seek medical advice until the cause of this bleeding is firmly diagnosed.  From what you describe the cause is probably minor but in case no firm diagnosis can be reached then a colonoscopy is the more comprehensive test.

regards
Morecambe