Chronic abdominal pain: when the scans are clean and the alarm is not.

Pain that migrates, lasts seconds, covers a coin-sized patch or fires at a light touch is telling you where it comes from.

This page is about understanding the condition and the role the brain and nervous system can play in it. It is not a diagnosis. Your own clinicians know your case.

What chronic abdominal pain is

Acute abdominal pain, new and severe, can signal appendicitis, gallstones, a bowel obstruction or other emergencies, and this article is not about that. Chronic abdominal pain is pain that has persisted for weeks, months or years, often through a sequence of blood tests, ultrasounds, endoscopies and CT scans that have come back normal or found only incidental things.

A proper work-up looks for organ conditions such as inflammatory bowel disease, ulcers, gallbladder disease and endometriosis. In a large share of people it finds nothing, and the pain remains. Gastroenterology has a name for the most persistent version: centrally mediated abdominal pain syndrome, formerly called functional abdominal pain syndrome. It is defined as constant or near-constant abdominal pain for six months or more that is not tied to eating or bowel movements and is not explained by another condition.

If your pain comes with bowel changes, bloating or symptoms after meals, see our articles on irritable bowel syndrome and abdominal bloating, which cover overlapping territory.

The neuroplastic contribution

Neuroplastic symptoms are real symptoms produced by learned pathways in the brain and nervous system, a sensitized alarm system, rather than by ongoing damage or disease in the body. They are not imaginary and not 'all in your head', and because the brain can change, they are reversible.

The ATNS Index of Neuroplastic Symptoms takes a firm position on chronic abdominal pain. When pain has lasted weeks or months and diagnostic evaluation has found no cause, it is likely to be neuroplastic. The index says this likelihood rises with more 'yes' answers on its Neuroplastic Symptoms Context Questionnaire (which asks about life circumstances and symptom patterns) and with a higher score on its Hidden Stress Questionnaire. It also lists features of the pain itself that particularly support a neuroplastic origin:

• Migration. The pain moves from one place in the abdomen to another.
• Brief duration. Jabs lasting seconds at a time.
• Small area. A patch the size of a silver dollar or smaller.
• Triggered by light touch on the skin, which a diseased organ would not do.

The index is equally careful about the other direction. A few uncommon structural causes can escape testing, including mild Crohn's disease in the small intestine, early lymphoma infiltrating the stomach or bowel, Addison's disease (insufficient adrenal function), lead poisoning, poor blood supply to the bowel, and small scattered abdominal tumours below CT resolution. So if a person has no significant psychosocial stress, or their pain does not improve when stress is addressed, the index advises reappraisal by a physician. Learn more about the shared mechanism in our guide to central sensitization.

What the research shows

The medical literature on centrally mediated abdominal pain syndrome (CAPS) matches the index closely. A review of the condition describes central sensitization, a maladaptive plasticity within the central nervous system in which pain pathways become disinhibited, as the core driver, and notes that changes in the brain and spinal cord appear to matter more than changes in the gut's own nerve endings.

A clinical study of the characteristics and related factors of CAPS found that depression, along with not exercising, was an independent risk factor, and a related analysis found anxiety and depression to be independent predictors. This fits the index's emphasis on hidden stress: the emotional state of the person is part of what keeps the pain circuit active.

Expert guidance on functional abdominal cramping pain recommends that people with a centrally mediated pattern may respond to low-dose neuromodulating medications, which work on nerve signalling rather than on any organ, a further sign of where the problem lives. The direction of the evidence is consistent: unexplained chronic abdominal pain is usually a nervous-system problem.

Signs the brain may be part of the picture

• Blood tests, imaging and endoscopy have found nothing to explain the pain.
• The pain moves around, lasts seconds at a time, or covers a small spot.
• Light touch on the skin of the belly sets it off.
• It is worse with stress, conflict or worry, and eases when you are absorbed in something.
• It began during or after a stressful period, a loss, or a frightening illness.

A solution that addresses it

There is an approach that addresses the brain's contribution to abdominal pain: pain reprocessing. It brings together education about neuroplastic symptoms, somatic tracking (attending to the belly with curiosity instead of fear), reducing threat, a graded return to eating, activity and social life, emotional awareness and expression, and acceptance and commitment skills. Trained clinicians deliver it, and digital programs increasingly make it available at home.

Cindra is a daily AI companion built around these approaches, offering daily check-ins, short practices and plain-language lessons for people whose symptoms have a neuroplastic component. You can join the waitlist.

What to do next

Make sure the evaluation has been thorough. Ask your clinician whether the uncommon causes the index names have been considered, and report any of these promptly: unintended weight loss, blood in the stool or black stools, fever, vomiting, pain that wakes you from sleep, a new change in bowel habit, severe pain after eating, or dizziness and salt craving. New, severe or rapidly worsening abdominal pain is an emergency.

If the work-up is clean, ask whether your pain fits a neuroplastic pattern, and take an honest look at the stress in your life, including the kind you are used to pushing aside. Then start learning and practising. Our guides to hurt versus harm and mindfulness practices are good starting points. If your pain does not change as stress is addressed, go back to your physician for reappraisal, as the index advises.

This article is for general education and is not medical advice, and it does not diagnose or treat any condition. Persistent symptoms deserve a proper medical assessment to rule out disease or injury before a neuroplastic explanation is considered. If your symptoms are new, changing, or come with red-flag signs such as fever, unexplained weight loss, numbness or weakness, chest pain, or loss of bladder or bowel control, see a clinician promptly.