abdominal cramps, aching, stool is somewhat inconsistent

For the past two months I have been getting an odd feeling in the area around my belly button, on the left side, down one inch diagonally. However it can above the belly button as well, also to the left. It has only been the second month that I have noticed the feeling each day. It is pretty much a dull ache, with an occasional "attack" of a more intense cramping feeling typically only once in a day. The area also feels rather stiff when I stretch the abdomen, and I do feel pain sometimes when coughing, laughing or bending over. There have also been times where I have what feels like a muscle spasm that extends from the area I mentioned up the left side of my abdomen to around the midsection. There is no pain when pushing on the area.
When going to the bathroom I have noticed that my stool is somewhat inconsistent. Sometimes it is normal, sometimes it is ribbon like, sometimes it is broken into a number of pieces, and sometimes it is mucous. Recently when I had gone to the bathroom I noticed a few specs of what appeared to be bright red blood. If it matters this feeling started while I was recovering from what was either a really bad cold or bronchitis. And I am an 18 year old male.