Irritable Bowel Syndrome (IBS) is a common, long-term condition of the digestive system. Its symptoms can be distressing and significantly affect your quality of life. However, a clear understanding of this condition can help manage the symptoms better. Here are several factors that need consideration when assessing IBS:

1. Symptoms: The primary symptoms of IBS include abdominal pain or discomfort, bloating, and a change in bowel habits, such as diarrhea, constipation, or both. The pain or discomfort often improves with a bowel movement.

2. Rome IV criteria: These are commonly used diagnostic criteria for IBS. They require recurrent abdominal pain on average at least 1 day/week in the last 3 months, associated with two or more of the following: related to defecation, associated with a change in frequency of stool, or associated with a change in form (appearance) of stool.

3. Absence of "Red Flags": Red flags are symptoms that may indicate a more serious condition. In the context of IBS, these might include unintended weight loss, blood in the stool, a family history of colorectal cancer or IBD, fever, or anemia.

4. Duration of symptoms: The Rome IV criteria also state that symptoms should have been present for at least 6 months before the diagnosis of IBS is made.

5. Impact on Quality of Life: IBS can significantly affect quality of life. People with IBS often report reduced productivity, limitations in daily activities, and negative impacts on social and emotional well-being.

6. Exclusion of other conditions: IBS is a diagnosis of exclusion. This means other medical conditions with similar symptoms, such as inflammatory bowel disease, celiac disease, and colorectal cancer, must be ruled out.

7. Psychosocial factors: Psychological stress and mental health conditions, such as anxiety and depression, are often linked with IBS. They don't cause IBS, but they can exacerbate the symptoms.

8. Dietary factors: Certain foods and drinks may trigger IBS symptoms in some people. These can include fatty or spicy foods, alcohol, caffeine, and specific types of carbohydrates known as FODMAPs.