21 w/blood mixed in stool, on/off abdominal pain, irregular movements. What's wrong

[Tyggie]

Hey guys, I have had a history with irregular bowel movements for a while (constipation followed by diarrhea, then some regular bowel movements in between) but the stools always looked normal. But since the past few months I've had this dull feeling on the right side of my abdomen (on the ascending colon), it sometimes goes away when I pass gas, but my stools have still always looked normal so I didn't worry about it. More recently, like for the past week I've had something that looks like blood mixed in every stool. It's not a large amount of blood but definitely noticeable. I have a lot of bloating now and smelly gas. And I also have mucus in my stool now. The stools are also loose now and fall in chuncks. Sometimes it's a lot and it looks like it's mixed with bile (dark brown color). The red spots are mixed in and they are a normal red color mostly, sometimes they're a little dark. Sometimes parts of the stool are lighter than others. I went to the doctor today and I had a blood test done and an ultrasound scheduled. It'll be a few days before the ultrasound and then a few more days until he gets the results. If everything comes back negative then he said a colonoscopy will be scheduled. I'm really anxious and nervous to wait that long. I'm only 21 with no family history of cancer problems. My dad was diagnosed with ulcerative colitis 3 years ago but he was 63 at the time. The new symptoms happened so suddenly, what could possibly be wrong?