Centrally Mediated Abdominal Pain Syndrome
WHAT IS CENTRALLY MEDIATED ABDOMINAL PAIN SYNDROME?
Centrally mediated abdominal pain syndrome (CAPS) is a gastrointestinal disorder in which there is continuous, almost continuous, or frequent and repeated abdominal pain that is not related to bowel habits and that does not occur in a specific location.
CAPS is not caused by any physical or metabolic disorders and findings from medical tests are usually normal. CAPS is caused by a change in how the brain receives and interprets pain signals from the gut. The miscommunication between the nerves of the gut and the brain causes heightened pain sensation.
CAPS is less common when compared to other disorders of the gut-brain interaction (DGBI), such as irritable bowel syndrome. The combination of adverse life events, and stress can influence the development of CAPS. The condition is seen more in women than in men. It is an exaggerated perception of pain in the brain despite normal stimulation in the gut.

SYMPTOMS
Symptoms of CAPS include:
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Continuous or nearly continuous abdominal pain
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The pain is not, or only occasionally, related to physiological events (for example: eating, bowel movements, or menstrual periods)
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Pain limits some part of daily functioning (for example: work/school, intimacy, social/leisure time, family life, and caregiving for yourself and others)
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Pain is not explained by another structural or other medical condition
It is important to discuss with your healthcare provider if you fit the criteria for CAPS
DIAGNOSIS
There are conditions that can cause abdominal pain and your healthcare provider will try to determine the cause. A detailed history of your pain and your current symptoms will be the first place to start. If appropriate, your healthcare provider may arrange some tests to investigate the cause of your pain. If the test results do not show any cause for your pain, your provider may consider a diagnosis for CAPS. There is no test available to diagnose CAPS. Its diagnosis is based on a careful assessment of your pain history.
TREATMENT
There is currently no cure for CAPS. Once a diagnosis for CAPS has been made, the focus is on the management of symptoms. It is important to understand how the pain impacts your life and what triggers worsening of your pain.
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Treatment for CAPS is individualized and the goal is to make symptoms more manageable. It is important to remember that it is a trial-and-error process and results are not always immediate. Having a good and trusting relationship with your healthcare provider is the key to navigating through your treatment options.
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There are both medications and non-medication methods for managing the symptoms of CAPS. For some people, medications alone work very well and other times, it is a combination of medications and other therapies. Consistent follow-up with your healthcare provider is important to review how you respond to treatment and to discuss if the current treatment needs to be changed.
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Medications for CAPS
Neuromodulators are a class of medications used to help manage CAPS. These medications calm the hypersensitive nerves lining the gut which then decrease pain. These medications are often also used for depression but at much higher doses. At lower doses, they work very well for gut nerve pain.

Tricyclic Antidepressants
Examples: amitriptyline, desipramine
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Side Effects:
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drowsiness
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constipation
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increased appetite
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weight gain
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dry mouth
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dry eyes
Serotonin-norepinephrine reuptake inhibitors (SNRI)
Examples: duloxetine
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Side Effects:
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nausea
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agitation
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dizziness
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sleep disturbance
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fatigue
Psychological Support
Psychological therapies such as mindfulness-based therapies, hypnotherapy, and psychodynamic-interpersonal therapy have shown to work well when combined with medications. These therapies teach you how to recognize your pain and develop coping strategies to make them more manageable.
