It's not possible for us to confirm if you have IBS. It's great that you have a colonsocopy scheduled. Your doc should be able to give you a firm dx after that test is completed.
The symptoms you described are certainly part of the overall profile of IBS but they are also shared symptoms of many other bowel problems. A colonoscopy is primarily beneficial in that it will rule out more serious conditions like IBD, Chrons, polyps, etc. IBS is generally the default dx when all other conditions are eliminated. For a true dx of IBS,
The Rome III Criteria are the current standard for this definition.
The Rome diagnostic criteria of Irritable Bowel Syndrome always presumes the absence of a structural or biochemical explanation for the symptoms and is made only by a physician.
Irritable Bowel Syndrome can be diagnosed based on at least 12 weeks (which need not be consecutive) in the preceding 12 months, of abdominal discomfort or pain that has two out of three of these features:
1. Relieved with defecation; and/or
2. Onset associated with a change in frequency of stool; and/or
3. Onset associated with a change in form (appearance) of stool.
Symptoms that Cumulatively Support the Diagnosis of IBS:
1. Abnormal stool frequency (may be defined as greater than 3 bowel movements per day and less than 3 bowel movements per week);
2. Abnormal stool form (lumpy/hard or loose/watery stool);
3. Abnormal stool passage (straining, urgency, or feeling of incomplete evacuation);
4. Passage of mucus;
5. Bloating or feeling of abdominal distension.
Supportive Symptoms of IBS:
1. Fewer than three bowel movements a week
2. More than three bowel movements a day
3. Hard or lumpy stools
4. Loose (mushy) or watery stools
5. Straining during a bowel movement
6. Urgency (having to rush to have a bowel movement)
7. Feeling of incomplete bowel movement
8. Passing mucus (white material) during a bowel movement
9. Abdominal fullness, bloating, or swelling
Red Flag symptoms which are NOT typical of IBS:
Pain that often awakens/interferes with sleep
Diarrhea that often awakens/interferes with sleep
Blood in your stool (visible or occult)
Abnormal physical examination