Functional Abdominal Pain Syndrome (FAPS) is abdominal pain where there is no obvious medical cause found. Functional Abdominal Pain Syndrome may also be referred to as Chronic Functional Abdominal Pain (CFAP). 
Functional abdominal pain means that the pain has no ‘organic’ cause. This basically means there is no physical cause for the pain. For example, a physical cause for abdominal pain could be something simple like constipation or something more complex like appendicitis or gut infections. In FAPS there is no such physical cause.
Patients may have to undergo a wide variety of tests and investigations before a diagnosis of functional abdominal pain is reached. FAPS is more a diagnosis of exclusion, this means healthcare professionals have excluded all other causes of abdominal pain.
FAPS is similar to Irritable Bowel Syndrome (IBS), however unlike IBS functional abdominal pain does not cause any other symptoms such as a change in bowel habit.
Functional Abdominal Pain can be an incredibly distressing condition for patients. Unlike “normal” conditions where a physical cause can be found and treated, FAPS does not have a physical abnormality which can be corrected and “cured”. Instead, other treatments are utilised such as low dose antidepressants.
