possible stomach or pancreatic cancer

I have had numerous tests done since mid-May for what started with chronic constipation. I could never go more than one or two days a week at best so I was taking Senokot twice a week for relief. I had experienced some tenderness and diffuse pain throughout abdomen with concentration on left side. All blood work was normal, so was FOBT and stool guaiac-all negative for blood. My first CT scan revealed a mild wall thickening of sigmoid-the CT was done with barium swallow and IV contrast dye. Then I started to get pain and pressure in middle of stomach-upper right quadrant below rib cage. I tried Metamucil and Benefiber to keep regular but they made me feel worse. I insisted on colonoscopy to put my mind at ease. Before test, even though I ran no fever, had no vomiting, and no diarrhea, my doctor put me on flagyl and cipro to ward off any infection. I got terribly nauseous, so he gave me augmentin, which gave me a lot of diarrhea. I had a second Ct and there was no colonic distention-this was also done with IV dye and barium. All organs were normal. Even my pelvic exam and transvaginal ultrasound revealed nothing-no masses or endo. I had my colonoscopy July 15, and it was normal. No biopsy was taken, no polyps, no cancer. They told me to repeat in five years. I started to feel O.K. again,and then about 2 and a half weeks ago, I had burning sensation in my stomach, so I demanded a blood test for h. pylori and a full CBC count. The blood count was immaculate, but I tested positive for h.pylori. I just finished a two week regimen on Saturday, October 4, of triple therapy-the PrevPav, one prevacid, one biaxin and two amoxicillin tablets twice a day-morning and night. I don't think the infection went away because I still feel the burn sometimes and pressure, mostly during the day. It does not keep me up at night. I sometimes have several bowel movements in one day. There is no blood in my stool, it is not diarrhea, but formed and normal color. I am scheduled with a follow-up with the gastroenterologist who performed the colonoscopy in November. Do you think I have a mass in my stomach or pancreas? I am scared an at my wit's end. Because of all the drugs, I have lost about 13 pounds since May-that's a five month period, but I have maintained my current weight for the past three months. I am having trouble gaining it back. Should I request an upper endoscopy, and a breath test to see if the infection went away and should I be worried about these frequent bowel movements? The discomfort does not keep me up at night. I stand 5 feet 5 inches and now weigh 118.3 I was around 131. It's as if right after I eat I have to have a bowel movement so I don't know if I am even keeping any nutrients in. Thank for your help.