Chronic abdominal pain

Chronic abdominal pain is defined as abdominal pain that persists for more than 3 months and occurs as a constant or intermittent pain syndrome. Intermittent pain can be considered recurrent abdominal pain. Chronic abdominal pain occurs after the age of 5. In 10% of children, there is a need to evaluate recurrent abdominal pain. About 2% of adults, mainly women, have chronic abdominal pain.

Almost all patients with chronic abdominal pain have had previous evaluation, but despite a thorough history, physical examination and evaluation have failed to establish a diagnosis. Perhaps 10% of these patients have an undiagnosed medical disorder, but many may have a functional disorder. Confirming whether a specific disorder (eg, adhesions, ovarian cyst, endometriosis) is the cause of symptoms or an incidental finding can be difficult.

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Causes and pathophysiology of chronic abdominal pain

Chronic abdominal pain can be caused by somatic diseases or functional disorders.

Functional abdominal pain syndrome (FAPS) is characterized by abdominal pain that persists for more than 6 months without evidence of underlying medical disorder, is not related to physiological factors (eg, eating, defecating, menstruation), and causes disability. Functional abdominal pain syndrome is poorly understood but probably involves changes in pain sensitivity. Sensory neurons in the dorsal horn of the spinal cord may become abnormally excitable or easily excitable in response to a combination of factors. Emotional and psychological factors (eg, depression, stress, cultural background, coping mechanisms) may cause efferent stimulation that amplifies pain signals, resulting in pain perception with a low pain threshold and pain persistence after the stimulus has ended. In addition, pain itself may act as a stressor, maintaining positive feedback.

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Diagnosis of chronic abdominal pain

Differential diagnosis between physiological and functional CABG can be quite difficult.

History and physical examination. Pain due to physiological causes is usually well localized, primarily to anatomical sites other than the periumbilical region. The pain may radiate to the back, and the patient awakens frequently. Examination findings that suggest a high risk of medical pathology include anorexia; persistent or recurrent fever; jaundice; anemia; hematuria; constitutional symptoms; edema; weight loss; blood in the stool; hematemesis; changes in bowel palpation, color, or discharge; abdominal distension, mass, or hepatomegaly. Intermittent pain due to structural changes usually has specific signs or is related to the nature and intake of food or bowel movements.

Functional chronic abdominal pain may resemble pain of somatic origin. However, common features indicating high risk and psychosocial features are absent. Onset of symptoms with physical exertion or sexual abuse may suggest functional chronic abdominal pain. A history of psychological trauma, such as divorce, miscarriage, or death of a family member, may be a clue to the diagnosis. Patients often have psychological disturbances or personality changes that may affect interpersonal relationships at work, school, family, and social interactions. Pain is often a major feature of the patient's life, leading to a "pain cult." A family history of chronic somatic complaints or pain, peptic ulcers, headaches, "nerves," or depression is characteristic.

Somatic causes of chronic abdominal pain

Reasons	Diagnostics
Genitourinary disorders
Congenital disorders	Intravenous urography, ultrasound
Urinary tract infection	Bacteriological urine culture
Pelvic inflammatory disease	X-ray and ultrasound examination of the pelvis, CT
Ovarian cyst, endometriosis	Gynecologist consultation
Gastrointestinal disorders
Hiatal hernia	Barium study
Hepatitis	Liver function tests
Cholecystitis	Ultrasound
Pancreatitis	Serum amylase and lipase levels, CT
Ulcer disease	Endoscopy, Helicobacter pylori test, stool occult blood test
Parasitic infestation (eg, giardiasis)	Stool examination for worm eggs or parasites
Meckel's diverticulum	Instrumental examination
Granulomatous enterocolitis	ESR, irrigography
Intestinal tuberculosis	Tuberculin test
Ulcerative colitis	Sigmoidoscopy, rectal biopsy
Crohn's disease	Endoscopy, X-ray examination, biopsy of the large and small intestines
Postoperative adhesive disease	Sequential examination of the upper gastrointestinal tract, barium passage through the intestine, irrigoscopy
Pancreatic pseudocyst	Ultrasound
Chronic appendicitis	X-ray examination of the abdominal cavity, ultrasound
Systemic disorders
Signs of intoxication	Blood test, red blood cell protoporphyrin levels
Henoch-Schönlein purpura	Anamnesis, urine analysis
Sickle cell anemia	Cell identification, hemoglobin electrophoresis
Food allergy	Food Exclusion
Abdominal epilepsy	EEG
Porphyria	Porphyrins in urine
Familial thalassemia major, familial angioedema, migraine equivalent	Family history

Children with functional chronic abdominal pain may have developmental delays, unusual dependence on parents, anxiety or depression, fear, tension, and a doctrine of moral improvement. Often, parents perceive the child as inadequate because of family relationships (e.g., only child, youngest child, only boy or girl in the family) or because of a medical problem (e.g., colic, feeding problems). Parents are often overly concerned with protecting the child.

Survey

In general, routine investigations (including urinalysis, complete blood count, liver function tests, ESR, amylase, and lipase levels) should be performed. Changes in these tests or the presence of suspicious symptoms and signs require further investigation, even if the previous investigations were negative. The use of specific investigations depends on the previous findings, but commonly used are CT of the abdomen and pelvis with contrast, upper GI endoscopy and colonoscopy, and, if necessary, small bowel radiography.

The informativeness of studies without pathognomonic symptoms and signs is extremely low. Thus, more than 50% of patients should undergo colonoscopy; less than 50% can be under observation or they should undergo CT of the abdomen and pelvis with contrast, if this study is appropriate. ERCP and laparoscopy are usually uninformative in the absence of specific symptoms.

Between the initial examination and the follow-up visit, the patient (or family, if the patient is a child) should note the occurrence of any pain, including its nature, intensity, duration, and any triggers or exacerbators. Food, stool, and any medications taken (and the results) should be recorded. This report may demonstrate inconsistency between behavior and hyperresponsiveness to pain or, if not, suggest the diagnosis. Individual questioning is needed regarding whether milk or dairy products trigger abdominal cramping, flatulence, or bloating, as lactose intolerance is common, especially in blacks.

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Prognosis and treatment of chronic abdominal pain

Somatic causes of pain are subject to treatment. If a diagnosis of functional chronic abdominal pain is established, frequent examination and testing should be avoided, since the patient may constantly focus on this, which will lead to an increase in complaints or the emergence of suspicion that the doctor is unsure of the diagnosis.

There are currently no treatments to cure functional chronic abdominal pain; however, there are many palliative measures. These measures rely on an element of trust, empathy between the physician and the patient and family. The patient must be assured that he or she is out of danger; specific patient problems must be clarified and resolved. The physician must explain the laboratory results, the nature of the complaints and the mechanism of pain, as well as why the patient experiences pain (i.e., constitutional differences in pain perception over time and work). It is important to avoid maintaining the negative psychosocial consequences of chronic pain (e.g., prolonged absence from school or work, withdrawal from social activities) and to promote a sense of independence, social participation, and self-confidence. This strategy helps the patient to control and not perceive symptoms, fully participating in daily activities.

With the exception of rare nonsteroidal anti-inflammatory drugs and sometimes tricyclic antidepressants, other medications are ineffective. Opiates should be avoided because they invariably lead to dependence.

Cognitive techniques (e.g., relaxation training, biofeedback, hypnosis) may be effective in contributing to the patient's sense of comfort and control over life. Regular follow-up visits should be weekly, monthly, or bimonthly, depending on the patient's needs, and should continue until the problem is resolved. Psychiatric care may be needed if symptoms persist, especially if the patient is depressed or there are significant psychological problems in the family.

School personnel should be involved in the management of a child with chronic abdominal pain. The child should be given the opportunity to rest briefly in the nurse's office during the school day with the expectation of returning to class within 15 to 30 minutes. The school nurse may be authorized to prescribe a mild analgesic (eg, acetaminophen). The nurse may occasionally allow the child to call the parents, who should support the child's stay at school. However, if the parents do not view their child as ill, the symptoms may worsen rather than improve.