I've Been Having A Lot Of Symptoms Lately I Just

I've been having a lot of symptoms lately I just want to know if it something serious, everytime I try to pass stool I feel something is blocking my ablilty to pass and when I try gas just comes out. I had rectum bleeding not a lot but enough to notice but the doctor said it was normal I don't think it is. I feel tired all the time now my lower back hurt and I have shocking pain in my stomach . I told my mom about it but she says it's just because I'm constiapted which I'm not because when I pass stool it's soft, if I want to pass stool I have to push so hard and it hurts, I just want to know what's going on . If you can please help me thank you .