Colon Cancer Forum - Need Advice On Continual Mild Abdominal Discomfort

I am a 48 year old white male, with no family history of colectoral cancer, although my father did have prostate cancer. I have never had a colonoscopy. My older brother had one a few years ago at age 51 and everything was normal for him with no polyps.

My discomfort began nov 13, during a routine annual checkup which included palpation to the abdomen. I felt a momentary sharp pain in the left abdomen, and since then i've felt a continual mild discomfort and somewhat of a swollen feeling in the same proximity. It seems aggravated if I jog. I'm not constipated, my bowel movements have been normal, and I haven't noticed any connection between my symptoms and eating or having bowel movements or passing gas. Fasting 30 hrs seemed to make no difference.

As the doctor palpated on the 13th, he suspected a mass in the upper colon area and advised an abdominal ct scan. Results of the ct scan on nov 17, were as follows:
------------------------------------------
"consecutive thin axial sections were taken from the diaphragm to the proximal thighs following oral and intravenous contrast enhancement."

"the liver, spleen, pancreas, and adrenals all appear normal without masses. While the right kidney appears normal, there is a 1 centimeter water attenuating mass projecting from the left lower pole laterally. Limited images through the gallbladder appear normal."

"in the pelvis, the silhouettes of the prostate, seminal vesicles, and unopacified bladder appear normal."

"a few small diverticula are suggested in the rectosigmoid, and there may be a few barium filled diverticula in the transverse colon. No small bowel or mesenteric pathology, lymphadenopathy, or ascites is seen. There is atheromatous disease in the aorta without aneurism. Limited images through the lung bases appear clear."

"impression: negative exam except for what may be mild diverticulosis which could be further evaluated with a barium enema and a small simple cyst of the left kidney."
------------------------------------------

my abdominal discomfort has not subsided, so I saw my doctor again on dec 2. He palpated more gently and did not feel a mass, but my mild discomfort remains (to this day). Since i've heard that a colonoscopy is the "gold standard" for colorectal diagnoses, and since any polyps that might be discovered can be removed during the procedure, I requested that he refer me for a colonoscopy and he agreed.

My colonoscopy is scheduled for january 15th with a doctor who was highly recommended to me, but I am quite concerned now about waiting another 40 days. Here are my questions:

1.) don't my symptoms warrant more immediate attention and action?

2.) should I be aggressively seeking an earlier exam, even if it means going to a less experienced doctor?

3.) should I forego a colonoscopy if a barium enema could be done more promptly?

4.) can someone suggest possible causes of my symptoms any less serious than colon cancer? From everything I read about diverticulosis, it doesn't present with continuous mild abdominal discomfort, and palpation wouldn't have irritated it anyway.

5.) i'm wondering if the left kidney or its cyst might have been bruised somehow during deep palpation, causing my symptoms. I'm thin.

Thanks in advance for any replies.