There are no laboratory analysis or radiation or binoculars or any means of checking one confirm the presence of the disease.
Diagnosis depends on a highly detailed description of the symptoms and through conscious questioning of the patient's doctor and taking a good patient history. But according to scientific criteria and conditions set by a scientific committee and is studying the scientific community as (Rome Criteria).
But to clarify important information that the presence of abdominal pain with swelling and discomfort subside after entering the bathroom and output, is the most important of these standards for diagnosis and can not diagnose IBS without repeating these pains for a cumulative period of up to three months per year.
That puts a difference between irritable bowel syndrome and chronic constipation, which is very different and important to differentiate between them in the diagnosis of the importance that the success of treatment in both cases and show also that the rest of means such as endoscopes and laboratories may be contributing factors in the diagnosis by demonstrating the absence of Pathogenesis colonic other.
It is also clear that aids (especially colonoscopy) may be important and essential if IBS patients complained of symptoms reflect the presence of other diseases. Any what we call the danger signs (Red Flags) in patients diagnosed they line the colon nervous but began to show signs of other diseases such as colitis festering or Crohn's disease illness or disease Siljak or colon tumors.