Chronic functional abdominal pain (CFAP), also sometimes referred to as hyperalgesia, is the medical term for chronic pain of the abdominal region. It is not due to an abdominal disease but, rather, a problem in the function or physiology of the area and its relation to the brain.
The pain associated with CFAP occurs when the nervous signals from the gut to the brain indicate that something is wrong, resulting in the sensation of pain. Therefore, it is an abnormality of the nervous system, rather than a problem of the abdominal region.
Females are more likely to be affected than males, although the reason for this is not clear. Additionally, there is a high incidence of childhood physical or sexual abuse in patients with CFAP, in comparison to the general population.
Patients with CFAP tend to have abdominal pain that lasts for a long time, without the presence of an abdominal disease. It is usually described as a dull or achy pain, which is why many people tend to delay diagnosis (in contrast to shaper or more severe pain.)
As there is no real cause for the pain in the abdominal region, patients with CFAP do not experience other symptoms such as weight loss, fever or rectal bleeding. However, patients may concurrently suffer from a gastrointestinal disorder such as diverticulosis, Crohn’s disease or a hiatus hernia, leading to other symptoms of the gastrointestinal tract.
The diagnosis of CFAP requires extensive medical testing to determine the underlying cause of the pain. This may include a range of tests such as:
- Blood tests
- Computed tomography (CT) scans
The results from these tests are usually normal and do not show any real cause for the chronic abdominal pain. This complicates treatment of the condition because the root of the pain cannot be treated.
Many patients with CFAP have a medical history multiple abdominal surgeries in an attempt to cure the pain, although the pain returns after the surgery, often worse than previously.
It is useful for patients to keep a pain diary to record the nature of the pain, including triggers for flare-ups of the pain, such as emotional or situational stress.
The aim of treatment for patients with CFAP is to control the symptoms so that the quality of life of the patient can be improved. In most cases, complete relief of the pain is not possible, but treatment can help reduce the severity of the pain and the impact on daily activities.
Traditional analgesic medications are not usually effective as there is no specific cause of the pain.
Non-pharmacological management techniques include:
- Meditation and other stress management techniques
- Hypnosis to rewire brain and refocus thoughts away from pain
- Behavioral therapy to change perception and behavior related to pain
Additionally, there are several medications that may be beneficial in the management of CFAP. For example, tricyclic antidepressants (e.g. amitriptyline) may be prescribed to stimulate certain nerve signals that may help to block the impulses of pain from the abdomen. The effect of these medications can take several weeks to become evident, so it is important that patients continue taking the medication for at least two months to experience the full effect.
Selective serotonin reuptake inhibitors (SSRIs) can also sometimes help to relieve other chronic symptoms such as sleep disturbance, restlessness and diarrhea.