M/27 symptoms: red blood in diarrhea for about 2 months stomach hurts on upper right side only. when poop is more solid it is thin. upper endoscopy was normal. colonoscopy in a few days. what could this be, does ibd affect only one part of stomach?

With red blood in your stool, a problem in the lower GI tract is most likely, which goes along with your normal upper endoscopy. Inflammatory bowel disease generally involves the lower intestine and often the colon; colonoscopy is a logical next step. By "stomach" do you mean abdomen? The stomach itself is not involved in IBD, but usually only parts of the intestine ("spotty") are involved.

Certainly from your description of the symptoms, inflammatory bowel disease as possible. Depending on what type of IBD it is, it can affect anywhere in the digestive tract. I agree that a colonoscopy is a good next step. Good luck.

The colonoscopy will provide you with an answer. A fecal calprotectin level that is substantially elevated is good evidence that you're dealing with inflammatory bowel disease.