Are these symptoms normal?! I am scared!!

I have bowel issues, where I have feelings of incomplete bowel movements, often, sometimes alternating from constipation, and diarrhea, mostly constipation. I am straining when I have a bowel movement, I do get a "full" feeling, and dull pain, on the left side of my abdomen. It gets better when I have a bowel movement, but it starts back up once I eat something. I have not lost weight, in fact, im gaining weight, and there is no blood in my stool. I do have clear mucus in my stool often. My main complaints are the feeling of incomplete bowel movements, and the "full" feeling in the left side of my abdomen under the rib cage. Some days are worse than others. I am male, 25, and there is no family history of colon cancer. What is this im concerned thank you.