Psychogenic abdominal pain: diagnosis and treatment

The term "psychogenic pain" is outdated and often stigmatizing. Today, physicians use the terms disorder of gut-brain interaction (DGBI) and centrally mediated abdominal pain syndrome (CAPS). These conditions are characterized by persistent or frequently recurring pain that is not explained by active organic disease, with central sensitization and dysregulation of the gut-brain axis playing a key role. The pain is real, caused by changes in pain processing in the nervous system, and not a patient's imagination. This approach is enshrined in the Rome IV documents and specialized reviews. [1]

CAPS (formerly "functional abdominal pain syndrome") is a subtype of DGBI characterized by near-constant or very frequent pain, typically poorly related to eating and bowel movements, and often leading to a significant reduction in quality of life. The Rome IV criteria emphasize the "central" nature of the pain and its relative independence from bowel motility, which helps distinguish CAPS from irritable bowel syndrome or functional dyspepsia. [2]

It is important to distinguish between CAPS/DGBI and somatic symptom disorder (SSD) according to the DSM-5. The latter describes a situation in which somatic symptoms (including pain) are combined with excessive anxiety, health-related thoughts, and behaviors, leading to significant distress/impaired functioning. A DSM-5 diagnosis does not eliminate the need for a medical assessment but adds a psychological treatment goal. [3]

Despite the absence of organ failure, patients with DGBI often have biological factors: visceral hypersensitivity, microbiota disturbances, and altered pain perception/modulation in the central nervous system. Therefore, the modern strategy is a biopsychosocial model: we treat the "gut," the "brain," and behavior, removing stigma and explaining the neurobiology of pain. [4]

When to be wary and act quickly

Although CAPS and other DGBIs are conditions without underlying organic inflammation or obstruction, new "warning" signs require a reconsideration of management. Don't dismiss everything as "psychogenic" if the following signs appear—they increase the likelihood of an organic cause.

Table 1. Red flags for chronic abdominal pain

Sign	What to exclude first
Progressive weight loss, anemia, blood in the stool, waking up at night from pain	Inflammatory bowel diseases, neoplasms
Fever, persistent vomiting, jaundice	Infection/cholangitis, obstruction, pancreatitis
Onset after 55-60 years or rapid deterioration	Oncosearch, vascular pathology
In women: acyclic pelvic pain, dyspareunia	Endometriosis, gynecological causes
Postoperative abdomen, bloating + gas/stool retention	Adhesive obstruction

These signs warrant targeted imaging/endoscopy and extensive testing, even if DGBI has previously been diagnosed. This selection of "red flags" is recommended by specialized societies. [5]

Diagnostics: How to Confirm CAPS/DGBI and Not Miss Organics

The first step is to confirm that the pain is chronic (more than 3 months) and understand its relationship with food, bowel movements, stress, and exercise. In CAPS, pain is typically only slightly related to food intake and bowel movements and can be nearly continuous, with a significant impact on daily activities. This phenotype distinguishes CAPS from IBS (pain associated with bowel movements/changes in bowel habits) and dyspepsia (possibly after meals, "in the pit of the stomach"). [6]

Basic laboratory testing for chronic pain without any "red flags" includes a complete blood count, C-reactive protein, basic biochemistry, and urinalysis. For diarrheal symptoms in adults, celiac disease serology is recommended; if there is doubt between DGBI and inflammatory bowel disease, calprotectin is recommended. Invasive and radiological diagnostics are indicated based on clinical suspicion, not "just in case." This approach reduces overdiagnosis and anxiety. [7]

If the pain is virtually constant, the examination is "clear," and there is minimal association with food/stool, CAPS is likely. Rome IV and a review of central visceral pain emphasize the role of central sensitization and that focusing on searching for "hidden organics" after a reasonable minimum of investigations only worsens outcomes due to a vicious cycle of anxiety and procedures. [8]

Separately assess psychological factors and criteria for somatic symptom disorder (DSM-5): excessive thoughts/behaviors around symptoms, high levels of health anxiety, significant functional impairment. This is not a "label," but a guideline for the addition of psychotherapy, and sometimes pharmacotherapy for anxiety/depression. [9]

Treatment: What Really Works (Tiered Plan)

1) Explaining the diagnosis and “removing the stigma”

Explain clearly: the pain is real, the mechanism is central sensitization and pain regulation dysfunction on the gut-brain axis. Treatment goals are realistic: to reduce pain and its impact on sleep, work, and activity, not to "turn off" all sensations instantly. This biopsychosocial frame reduces fear and improves adherence. [10]

2) Psychological methods - first-line therapy

Cognitive behavioral therapy and gut-directed hypnotherapy (GDH) have been shown to reduce pain and global symptoms in DGBI/IBS, including refractory cases. Evidence has also emerged for digital/remote GDH programs. These methods alter pain processing and reduce catastrophizing. [11]

3) Pain neuromodulators

For pain-dominant conditions, low-dose tricyclic antidepressants (e.g., amitriptyline) are preferred—they reduce visceral hypersensitivity and improve sleep; alternatively, SNRIs/SSRIs can be considered as indicated. Titration should be "slowly upwards"; reassess the effect every 4-8 weeks. These are standard approaches in DGBI and centrally mediated pain. [12]

4) What doesn't help or is harmful

Opioids are contraindicated in chronic non-oncologic abdominal pain: they increase hyperalgesia and the risk of narcotic bowel syndrome (NBS). If opioids are present, gradual withdrawal with support is recommended, and pain is managed with neuromodulators and psychological interventions. This is reflected in the interdisciplinary approach (DGBI/pain). [13]

Special groups and situations

Children and adolescents. For pediatric functional abdominal pain disorders (FAPDs), protocols and new ESPGHAN/NASPGHAN guidelines have been published, focusing on family education, activity restoration, and step-down therapy (dietary support, psychotherapy, and medications when indicated). Practical algorithms have been proposed for the subtypes of FAP-NOS, IBS, and abdominal migraine. [14]

Co-occurring anxiety/depression or DSM-5 somatic disorder. Add targeted psychotherapy and, if necessary, low-dose pharmacotherapy for anxiety/depression with regular reassessment. This reduces pain intensity and frequency of visits. [15]

Telemedicine/digital solutions: Randomized trials show that digital GDH (mobile/online programs) improves pain and daily symptoms in patients with DGBI/IBS, increasing access to care. [16]

Step-by-step algorithm for conducting

Step 1. Eliminate “red flags,” collect a detailed pain history (relationship with food/stool/stress), medication history. Explain the biopsychosocial model. [17]

Step 2. Minimum tests (complete blood count, C-reactive protein, basic biochemistry, urine analysis; celiac disease in case of diarrhea; calprotectin in case of doubt). Without indications, do not expand the examination. [18]

Step 3. Classify: CAPS (pain is almost constant, not related to food intake/stool) vs. IBS/dyspepsia etc. Prescribe psychotherapy (CBT/GDH) as a basis. [19]

Step 4: Add a low-dose neuromodulator if pain persists; keep a symptom/function diary; reassess and adjust therapy after 4-8 weeks. [20]

Step 5. Avoid opioids; if available, plan for withdrawal and replacement with strategies with proven benefit. Involve a multidisciplinary team as needed. [21]

Tables for practice

Table 2. How to distinguish CAPS from other common DGBIs

Sign	CAPS	Irritable bowel syndrome	Functional dyspepsia
The nature of pain	Almost constant/frequent, "centralized"	Recurrent, associated with defecation/change in stool	Epigastric, associated with food intake (fullness/burning)
Food/stool connection	Weak	Expressed	Severe (after eating)
Key mechanism	Central sensitization	Visceral hypersensitivity + motility	Visceral hypersensitivity/gastric motility
First line	CBT/GDH, neuromodulators	Diet + CBT/GDH, drugs by subtype	Test-and-treat H. pylori/PPI, CBT as indicated

Table 3. Treatment tools and when to choose them

Tool	Who is it indicated for?	Comments
CBT (cognitive behavioral therapy)	All DGBI, CAPS, anxiety/catastrophizing	The basis of therapy, reduces pain and distress
Gut-directed hypnotherapy (in-person/digital)	DGBI/IBS, refractory cases	Effective for pain and global symptoms (meta-analyses, RCTs)
TCAs (low doses)	Pain dominance, sleep disturbances	"Slow Up", monitoring tolerance
SNRIs/SSRIs	Anxiety/depression, inadequate response to TCAs	As an analgesic adjuvant therapy
Opioid Elimination	All patients with chronic gastrointestinal pain	Prevention of NBS and hyperalgesia

Table 4. Minimum examinations for chronic pain without “red flags”

Test	For what
Complete blood count, C-reactive protein	Rule out inflammation/anemia
Biochemistry, urine analysis	General safety, associated reasons
Serology of celiac disease (in diarrhea)	An important and treatable mimic diagnosis
Calprotectin (depending on the situation)	Distinguishing inflammation from DGBI
Additional methods (ultrasound/CT/endoscopy)	Only on clinical hypothesis or "red flags"

Children's section

In children, the term FAPDs encompasses functional abdominal pain-ND (FAP-NOS), IBS, and abdominal migraine. The new ESPGHAN/NASPGHAN guidelines propose an algorithm: family education, support for return to activity/school, graded dietary and psychological interventions, and selective medication. The emphasis is on a positive diagnosis without excessive testing in the absence of "alarm." [22]

Frequently Asked Questions

• “If the cause is nerves, why get examined?”

A minimal investigation is necessary to rule out "red flags" and rare organic causes. But beyond a reasonable minimum, excessive testing is harmful: it increases anxiety and does not improve outcomes. [23]

• "Hypnotherapy - isn't it evidence-based?"

There are systematic reviews and RCTs, including digital ones, showing improvements in pain and global symptoms in DGBI/IBS. This is not a "placebo," but a method that redirects attention and reduces central sensitization. [24]

• "Antidepressants - does that mean it's all in my head?"

No. Low doses of TCAs and a number of other agents act as pain neuromodulators. They act on pain-processing pathways and reduce hypersensitivity—a biological treatment for real pain. [25]

• "Why not opioids?"

Opioids for chronic gastrointestinal pain increase the risk of hyperalgesia and narcotic bowel syndrome. Guidelines recommend avoiding them and using alternative strategies. [26]