Overview of FAPs
Functional abdominal painsyndrome (FAPs), also known as chronic idiopathic abdominal pain or chronic functional abdominal pain, refers to persistent or frequent episodes of abdominal pain, the duration of the disease more than half a year, but is not related to the gastrointestinal tract or the relationship between the functional diseases. It is often accompanied by other generalized discomfort or psychological disorders such as depression and anxiety, etc. The etiology and pathogenesis of FAPs are not well understood, and may be related to visceral sensitivities, brain-gut interactions leading to abnormal central pain regulation, and psychological abnormalities. FAPs are classified as somatic pain disorders and the diagnostic criteria are consistent with the diagnosis of somatic anomalies in psychiatric disorders. 2016’s Functional Gastrointestinal Diseases: Rome IV changed the term “functional abdominal pain syndrome” to “centrally mediated abdominal pain syndrome.” This change facilitates the understanding of the pathogenesis of these disorders and is consistent with the new view of brain-gut interaction, while minimizing the “stigma” of “functional”.
Etiology
The etiology and pathogenesis of FAPs are not well understood, and may be related to visceral sensitization, brain-gut interactions leading to abnormalities in central pain regulation, and psychological abnormalities. Current research suggests that FAPs may be a form of central pain, due to a variety of factors affecting the physiological regulation of normal intestinal function by the central nervous system, resulting in the amplification of normal endoregulatory signals in the central nervous system and the production of abnormal sensations, which leads to abdominal pain. It is not related to or has little to do with dysfunction of the dynamics and function of the bowel itself.
Symptoms
Patients with this disease are characterized by a number of symptoms: continuous pain sensations or recurrent episodes that begin in childhood, are persistent, and are not associated with eating or defecation. The pain is widespread and poorly localized, accompanied by nausea or stabbing pain. In severe cases, the pain may be accompanied by other generalized discomfort or psychological disorders such as depression or anxiety.
Examination
Patients with FAPS may protect their abdomen with their hands, show severe abdominal pain or be reluctant to allow the doctor to examine their abdomen, or even close their eyes out of fear. The patient often describes the abdominal pain very graphically when giving a history, but on physical examination, he or she is unable to pinpoint the site of the most intense abdominal pain.
Patients with FAPS may have myalgias, but when their attention is distracted, the myalgias may diminish or disappear.Patients with FAPS often complain of multiple sites of pressure pain or widespread pressure pain, but the somatic and expressive responses to the pressure pain are often inconsistent.
Patients with FAPS emphasize the presence of an abdominal mass; in fact, the abdominal mass referred to by the patient is often physiologic, such as the raphe and sigmoid collaterals. It should be emphasized that in patients with a proposed diagnosis of FAPS, it is important to look for signs supporting the diagnosis through physical examination on the one hand, and to be careful to exclude or detect organic disease, such as abdominal aneurysms, which are detected in 1/3 of cases on careful abdominal palpation.
Diagnosis
Functional abdominal pain syndrome is subject to the following conditions: (i) persistent or near-permanent abdominal pain; (ii) unrelated to or occasionally associated with physiologic behavior; (iii) partial loss of ability to perform daily activities; and (iv) does not meet the diagnostic criteria for other functional gastrointestinal disorders that could explain the abdominal pain. Symptoms have been present for at least 6 months prior to diagnosis, and the above diagnostic criteria have been met for the last 3 months.
Treatment
1. General treatment
Explain to the patient that the aim of treatment for this disease is to relieve tension and improve function. Regular follow-up is required. After 2 to 3 follow-up visits, the follow-up period can be extended to every 2 to 3 months.
2. Drug treatment
(1) Analgesic drugs Most analgesics are ineffective, which may be related to the fact that the target point of drug action is mainly in the periphery. Avoid the use of narcotic analgesics.
(2) Antidepressants or anxiolytics Antidepressants, especially tricyclic antidepressants, can exert both analgesic and antidepressant effects to relieve pain in patients with FAPs. Patients with highly somatized symptoms who cannot tolerate regular amounts of antidepressants may start with a very small amount of TCA and gradually increase the amount, or add other drugs.
(3) Anticonvulsants Anticonvulsants are effective in chronic pain syndromes such as chronic neuralgia and have fewer side effects, are relatively safer and less addictive, and can block the vicious cycle between pain and depression.
3.Psychotherapy
Cognitive-behavioral therapy can help patients improve their ability to control their symptoms, so that they can learn to deal with the great internal pressure brought by stressful events or anxiety.
4. Multidisciplinary treatment
A multidisciplinary treatment model can provide chronic pain patients with comprehensive, rational, and effective rehabilitation, which can help relieve intractable chronic pain and may help patients gradually get rid of painkillers. There is also an unexpected benefit of possibly discovering diseases that were originally missed.