Chronic abdominal pain (CAP) is pain that persists for more than 3 months either continuously or intermittently. Intermittent pain may be referred to as recurrent abdominal pain (RAP). Acute abdominal pain is discussed elsewhere. CAP occurs any time after 5 years of age. Up to 10% of children require evaluation for RAP. About 2% of adults, predominantly women, have CAP (a much higher percentage of adults have some type of chronic gastrointestinal [GI] symptoms, including nonulcer dyspepsia and various bowel disturbances).
Functional bowel disorders are common causes of chronic abdominal pain. Irritable bowel syndrome (IBS) is a functional bowel disorder that causes recurrent abdominal pain and altered bowel habits. Functional abdominal pain is a similar but less common disorder that does not cause altered bowel habits.
Nearly all patients with CAP have had a prior medical evaluation that did not yield a diagnosis after history, physical, and basic testing.
Pathophysiology
Physiologic causes of chronic abdominal pain (see table Physiologic Causes of Chronic Abdominal Pain) result from stimuli of visceral receptors (mechanical, chemical, or both). Pain may be localized or referred, depending on innervation and specific organ involvement.
Irritable bowel syndrome and functional abdominal pain cause pain that persists > 6 months without evidence of physiologic disease. The pathophysiology of these functional disorders is complex and seems to involve altered intestinal motility, increased visceral nociception, and psychologic factors. Visceral hyperalgesia refers to hypersensitivity to normal amounts of intraluminal distention and heightened perception of pain in the presence of normal quantities of intestinal gas; it may result from remodeling of neural pathways in the brain-gut axis.
Etiology
Perhaps 10% of patients have an occult physiologic illness (see Table: Physiologic Causes of Chronic Abdominal Pain); the remainder have a functional process. However, determining whether a particular abnormality (eg, adhesions, ovarian cyst, endometriosis) is the cause of CAP symptoms or an incidental finding can be difficult.
Physiologic Causes of Chronic Abdominal Pain
Cause |
Suggestive Findings* |
Diagnostic Approach |
Genitourinary disorders |
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Recurrent UTIs |
IVU Ultrasonography |
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Discomfort before or during menses |
Laparoscopy |
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Vague lower abdominal discomfort, bloating Sometimes a palpable pelvic mass |
Pelvic ultrasonography Gynecologic consultation |
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Fever, flank pain, dark or bloody urine |
Urine culture IVU CT |
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Sequelae of acute PID |
Pelvic discomfort History of acute PID |
Pelvic examination Sometimes laparoscopy |
Gastrointestinal disorders |
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In children, failure to thrive Abdominal bloating, diarrhea, and often steatorrhea Symptoms that worsen when gluten-containing products are ingested |
Serologic markers/HLA-DQ2/HLA-DQ8 haplotype testing Small-bowel biopsy |
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Several previous discrete episodes of RLQ pain |
Abdominal CT Ultrasonography |
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Recurrent colicky RUQ pain |
Ultrasonography |
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Upper abdominal discomfort, malaise, anorexia Jaundice uncommon In about one third of patients, a history of acute hepatitis |
Liver tests, international normalized ratio, albumin, and platelets Titers for viral, autoimmune, or metabolic causes of hepatitis |
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Episodes of severe epigastric pain Sometimes malabsorption (eg, diarrhea, fatty stool) Usually a history of acute pancreatitis |
Serum lipase levels (frequently not elevated) CT, MRCP Stool tests (fecal elastase or fecal fat) |
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Discomfort uncommon but possibly colicky discomfort if left colon is partially obstructed Often occult or visible blood in stool |
Colonoscopy |
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Episodic severe pain with fever, anorexia, weight loss, diarrhea Extraintestinal symptoms (joints, eyes, mouth, skin) |
CT enterography or upper GI series with SBFT Colonoscopy and esophagogastroduodenoscopy with biopsies |
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Dyspepsia or mild pain Often occult blood in stool |
Upper endoscopy |
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Granulomatous enterocolitis |
Family history Recurrent infections in other sites (eg, lungs, lymph nodes) |
ESR Colonoscopy CT enterography |
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Hiatus hernia with gastroesophageal reflux |
Heartburn Sometimes cough and/or hoarseness Symptoms relieved by taking antacids Sometimes regurgitation of gastric contents into mouth |
Barium swallow Endoscopy |
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Chronic nonspecific pain Sometimes palpable RLQ mass Fever, diarrhea, weight loss |
Tuberculin test Endoscopy for biopsy CT with oral contrast Chest x-ray |
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Bloating and cramps after ingesting milk products |
Hydrogen breath test Trial of elimination of lactose-containing foods |
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Severe upper abdominal pain that May cause obstructive jaundice |
CT MRCP or ERCP Endoscopic ultrasonography |
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Parasitic infestation (particularly giardiasis) |
History of travel or exposure Cramps, flatulence, diarrhea |
Stool examination for ova or parasites Stool enzyme immunoassay (for Giardia) |
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Upper abdominal pain relieved by food and antacids May awaken patient at night |
Endoscopy and biopsy for Helicobacter pylori H. pylori breath test or stool antigen assays Evaluation of nonsteroidal anti-inflammatory drug, alcohol, and tobacco use Stool examination for occult blood |
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Postoperative adhesive bands |
Previous abdominal surgery Colicky discomfort accompanied by nausea and sometimes vomiting |
Upper GI series, SBFT, or CT enterography Abdominal CT |
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Crampy pain with bloody diarrhea |
Sigmoidoscopy Rectal biopsy Colonoscopy |
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Systemic disorders |
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Abdominal epilepsy |
Very rare Episodic pain No other GI symptoms |
EEG |
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Recurrent severe abdominal pain, vomiting Benign abdominal examination Sometimes neurologic symptoms (eg, muscle weakness, seizures, mental disturbance) In some types, skin lesions |
Urine porphobilinogen and delta-aminolevulinic acid screening RBC deaminase assay |
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Family history Quotidian fever and peritonitis often accompanying the bouts of pain Starting in childhood or adolescence |
Genetic testing |
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Symptoms developing only after consuming certain foods (eg, seafood) |
Elimination diet |
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Immunoglobulin A–associated vasculitis (formerly Henoch-Schönlein purpura) |
Palpable purpuric rash Joint pains Occult blood in stool |
Biopsy of skin lesions |
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Family history Pain often with peripheral angioedema and fever |
Serum complement level (C4) during attacks |
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Cognitive/behavioral abnormalities |
Blood lead level |
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Rare variant with epigastric pain and vomiting Mainly in children Usually family history of migraine |
Clinical evaluation |
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Family history Severe episodes of abdominal pain lasting over a day Recurrent pain in nonabdominal sites |
Sickle preparation Hemoglobin electrophoresis |
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* Findings are not always present and may be present in other disorders. |
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EEG = electroencephalography; ERCP = endoscopic retrograde cholangiopancreatography; ESR = erythrocyte sedimentation rate; GI = gastrointestinal; IVU = intravenous urography; MRCP = magnetic resonance cholangiopancreatography; PID = pelvic inflammatory disease; RBC = red blood cell; RLQ = right lower quadrant; RUQ = right upper quadrant; SBFT = small-bowel follow-through; UTI = urinary tract infection. |
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Modified from Barbero GJ: Recurrent abdominal pain in childhood. Pediatr Rev 4(1):29–34, 1982, doi: 10.1542/pir.4-1-29, and from Greenberger NJ: Sorting through nonsurgical causes of acute abdominal pain. J Crit Illn 7:1602–1609, 1992. |
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Evaluation
History
History of present illness should elicit pain location, quality, duration, timing and frequency of recurrence, and factors that worsen or relieve pain (particularly eating or moving bowels). A specific inquiry as to whether milk and milk products cause abdominal cramps, bloating, or distention is needed because lactose intolerance is common, especially among blacks, Hispanics, Asians (particularly East Asian countries), and American Indians with increasing frequency with aging.
Review of systems seeks concomitant GI symptoms such as gastroesophageal reflux, anorexia, bloating or “gas,” nausea, vomiting, jaundice, melena, hematuria, hematemesis, weight loss, and mucus or blood in the stool. Bowel symptoms, such as diarrhea, constipation, and changes in stool consistency, color, or elimination pattern, are particularly important.
Diet history is important. For example, ingestion of large amounts of cola beverages, fruit juices (which may contain significant quantities of fructose and sorbitol), or gas-producing foods (eg, beans, onions, cabbage, cauliflower) can account for otherwise puzzling abdominal pain.
Past medical history should include nature and timing of any abdominal surgery and the results of previous tests that have been done and treatments that have been tried. A drug history should include details concerning prescription and illicit drug use as well as alcohol.
Family history of RAP, fevers, or both should be ascertained, as well as known diagnoses of sickle cell trait or disease, familial Mediterranean fever, and porphyria.
Physical examination
Review of vital signs should particularly note presence of fever or tachycardia.
General examination should seek presence of jaundice, skin rash, and peripheral edema.
Abdominal examination should note areas of tenderness, presence of peritoneal findings (eg, guarding, rigidity, rebound), and any masses or organomegaly. Rectal examination and (in women) pelvic examination to locate tenderness and masses and stool examination for occult blood are essential.
Red flags
Interpretation of findings
Clinical examination alone infrequently provides a firm diagnosis.
Determining whether CAP is physiologic or functional can be difficult. Although the presence of red flag findings indicates a high likelihood of a physiologic cause, their absence does not rule it out. Other hints are that physiologic causes usually cause pain that is well localized, especially to areas other than the periumbilical region. Pain that wakes the patient is usually physiologic. Some findings suggestive of specific disorders are listed in table Physiologic Causes of Chronic Abdominal Pain.
Functional CAP may result in pain similar to that of physiologic origin. However, there are no associated red flag findings, and psychosocial features are often prominent. A history of physical or sexual abuse or an unresolved loss (eg, divorce, miscarriage, death of a family member) may be a clue.
The Rome IV criteria for diagnosis of irritable bowel syndrome are the presence of abdominal pain for at least 1 day/week in the last 3 months along with at least 2 of the following:
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Pain is related to defecation.
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Pain is associated with a change in frequency of defecation.
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Pain is associated with a change in consistency of stool (1).
Evaluation reference
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1. Drossman DA: Functional gastrointestinal disorders: History, pathophysiology, clinical features, and Rome IV. Gastroenterology 150:1262–1279, 2016. doi: 10.1053/j.gastro.2016.02.032.
Testing
In general, simple tests (including urinalysis, complete blood count, liver tests, blood urea nitrogen, glucose, and lipase) should be done. Abnormalities in these tests, the presence of red flag findings, or specific clinical findings mandate further testing, even if previous assessments have been negative. Specific tests depend on the findings (see Table: Physiologic Causes of Chronic Abdominal Pain) but typically include ultrasonography for ovarian cancer in women > 50 years, CT of the abdomen and pelvis with contrast, upper GI endoscopy (particularly in patients > 60 years old) or colonoscopy, and perhaps small-bowel imaging or stool testing.
The benefits of testing patients with no red flag findings are unclear. Patients > 50 or with risk factors for colon cancer (eg, family history) should probably have a colonoscopy; patients ≤ 50 can be observed or have CT of the abdomen and pelvis with contrast if an imaging study is desired. Magnetic resonance cholangiopancreatography (MRCP), endoscopic retrograde cholangiopancreatography (ERCP), and laparoscopy are rarely helpful in the absence of specific indications.
Between the initial evaluation and the follow-up visit, the patient (or family, if the patient is a child) should record any pain, including its nature, intensity, duration, and precipitating factors. Diet, defecation pattern, and any remedies tried (and the results obtained) should also be recorded. This record may reveal inappropriate behavior patterns and exaggerated responses to pain or otherwise suggest a diagnosis.
Treatment
Physiologic conditions are treated.
If the diagnosis of functional CAP is made, frequent examinations and tests should be avoided because they may focus on or magnify the physical complaints or imply that the physician lacks confidence in the diagnosis.
There are no modalities to cure functional CAP; however, many helpful measures are available. These measures rest on a foundation of a trusting, empathic relationship between the physician, patient, and family. Patients should be reassured that they are not in danger; specific concerns should be sought and addressed. The physician should explain the laboratory findings and the nature of the problem and describe how the pain is generated and how the patient perceives it (ie, there may be a tendency to feel pain at times of stress). It is important to avoid perpetuating the negative psychosocial consequences of chronic pain (eg, prolonged absences from school or work, withdrawal from social activities) and to promote independence, social participation, and self-reliance. These strategies help the patient control or tolerate the symptoms while participating fully in everyday activities.
Drugs such as antispasmotics and tricyclic antidepressants can be effective. Opioids should be avoided because of the concern about potential dependency and possibility of narcotic bowel syndrome. Evidence supporting the use of probiotics for functional abdominal pain is currently limited.
Cognitive methods (eg, relaxation training, biofeedback, hypnosis) may help by contributing to the patient’s sense of well-being and control. Regular follow-up visits should be scheduled weekly, monthly, or bimonthly, depending on the patient’s needs, and should continue until well after the problem has resolved. Psychiatric referral may be required if symptoms persist, especially if the patient is depressed or there are significant psychologic stressors at home.
