While the exact presence of functional abdominal pain syndrome is unknown studies show that it affects between 0.5% and 2% of North Americans.
[1] Functional abdominal pain is usually periumbilical and is not accompanied by weight loss, vomiting, diarrhea, nocturnal symptoms, or slowed growth.
[2] Peripheral sensitization, also known as elevated ascending visceral afferent signalling, can happen following GI tract inflammation or damage.
[8] According to theory, this inflammatory infiltration results in increased sensitivity and field of peripheral receptors, the latter of which causes hyperalgesia by recruiting and activating nociceptors that were previously silent.
[2] Furthermore, it was discovered that the best indicators of who would develop PI-IBS were stress, as measured by traumatic life events, and a neurotic personality features.
[8] These convergent lines of data support the hypothesis that inflammation and/or injury in a psychologically predisposed person may cause visceral afferents to become peripherally sensitized, increasing the amount of nociceptive information that ascends to the spinal dorsal horn.
An increase in presynaptic glutamate release causes central sensitization by removing the magnesium ion block of the N-methyl-d-aspartate (NMDA) receptor.
The end result is an overall increase in dorsal horn neuron responsiveness, which frequently lasts longer than the initial shock when combined with the activation of other important enzymes.
Similarly, Carnett's sign, which involves palpating a sore spot both before and after the patient tenses their abdominal wall, could be helpful.
[2] Diagnostic testing to rule out organic disease should not be done frequently in the absence of alarm signs, similar to other functional GI problems (ie, unexplained weight loss, bloody bowel movements, abdominal mass, anorexia).
Functional gall bladder disease or sphincter of Oddi dysfunction should be considered if the pain is significant, occurs at different intervals (not daily), and is located in the right upper quadrant or epigastrium.
As a result, the majority of currently employed therapies are founded on data and firsthand knowledge from other functional bowel diseases and chronic pain syndromes.
[1] Trials utilizing tricyclic antidepressants have generally outperformed those using selective serotonin-reuptake inhibitors in other chronic pain disorders.
[1] Stress management, hypnosis,[17] dynamic or interpersonal psychotherapy,[18][19] and cognitive behavioral therapy are among the interventions that may prove advantageous.