Here is a symptom list for diagnosing IBS (you will see incomplete evactuation is definitely a symptom):
The Rome II Diagnostic Criteria (a system for diagnosing functional gastrointestinal disorders based on symptoms) for IBS is as follows:
At least 12 weeks or more, which need not be consecutive, in the preceding 12 months of abdominal discomfort or pain that is accompanied by at least two of the following features:
1) It is relieved with defecation, and/or
2) Onset is associated with a change in frequency of stool, and/or
3) Onset is associated with a change in form (appearance) of stool.
Other symptoms that are not essential but support the diagnosis of IBS:
- Abnormal stool frequency (greater than 3 bowel movements/day or less than 3 bowel movements/week);
- Abnormal stool form (lumpy/hard or loose/watery stool);
- Abnormal stool passage (straining, urgency, or feeling of incomplete evacuation);
- Passage of mucus;
- Bloating or feeling of abdominal distension.