lump inside rectum

I have been feeling there's a lump inside my rectum, change in bowel moments, no blood, loose stools,these are happening for the past two years can it be any kind of cancer, i m also feel very tired sleeping for 10 hours, age 21 male, I'm scared a lot

I think the best advice is to get it checked out.  A Dr could do a quick examination and if necessary you can have further tests at the hospital. There are blood tests which your Dr may suggest too. Try not to worry. Easy to say, I know... Bowel cancer is more common with older people I think. 

Does lump inside rectum is a symptom of any kind of cancer?

There are several things it could be, an abcess for instance.  As John has said, the best course of action is to see a doctor.  The point with all these things is that the sooner a diagnosis is achieved, the easier the problem is to deal with - so don't delay and get it seen to.