Abdominal pain in children: A comprehensive overview for parents & caregivers

Introduction to recurrent abdominal pain

Recurrent abdominal pain (RAP) in children is defined as at least three episodes of pain that occur over at least three months and affect the child’s ability to perform everyday activities. RAP is most often considered functional (non-organic) abdominal pain. 

However, an organic cause is found in 5-10% of cases.

Functional (non-organic) recurrent abdominal pain (RAP) presents commonly in general practice, and it causes a great deal of school absence and considerable anxiety. Most cases can be managed in primary care. Medication is not typically needed.

The initial approach adopted by primary care doctors is crucial to successful management. It involves thorough history and examination skills, understanding and awareness of red flags suggesting organic pathology, and the knowledge and consulting style that offers a straightforward and empowering approach to patients while avoiding unnecessary investigation.

There are several defined RAP patterns in children, of which pediatric irritable bowel syndrome (IBS) is the most common.

The original definition of RAP, published in 1958, includes organic and functional pain. The Rome Criteria (recently updated as Rome IV) narrowed the definition of functional pain and defined several specific clinical patterns. 

The Rome diagnostic criteria are expert consensus for diagnosing functional gastrointestinal disorders (FGIDs). Rome IV was released in May 2016. The Rome Criteria provide a symptom-based framework for approaching the diagnosis and management of RAP. 

This article follows these criteria and discusses RAP without organic cause.

Considering and excluding organic causes of recurrent abdominal pain in children is essential. However, it is also essential to provide support and reassurance for children with functional pain and their parents without allowing endless investigations for an organic cause to cause further distress and confusion. 

This article discusses the organic causes of abdominal pain as differential diagnoses.

Epidemiology

• RAP affects 10-20% of school-aged children worldwide.
• 3-8% of children with this pain pattern have a causative organic pathology (and are excluded from the Rome definition of RAP). They usually have ‘alarm’ features.
• RAP occurs most commonly between ages 5 and 14 years. It is uncommon in children under 5 years of age.
• Girls are more commonly affected than boys.
• There is an association between obesity and RAP.
• There is an association between stress and RAP. Children with RAP are more likely to have experienced events such as the deaths of family members, domestic violence, harsh punishment from parents, parental job loss and economic stress, hospitalization, and bullying.
• RAP appears unrelated to the socio-economic group.
• There is evidence for a genetic component.
• Children with a history of cow’s milk protein hypersensitivity or abdominal surgery have an increased prevalence of FGIDs years later.

Associated symptoms

• Children with RAP are more likely to have headaches, joint pain, anorexia, vomiting, nausea, excessive gas, and altered bowel symptoms. However, these symptoms may also occur in the presence of organic pathology. 

There is considerable overlap between recurrent headaches and abdominal pain.

• Children with RAP are more often diagnosed with anxiety or depressive disorders than unaffected children. Abdominal pain can cause depression/anxiety; once developed, abdominal pain and depression/anxiety worsen each other.
• RAP leads to increased functional impairment in everyday life and school absence. 80% of affected children report school absences of at least one day in the previous term, compared to 45% in a control group.

Risk factors for recurrent abdominal pain

• Parental anxiety in the first year of life is associated with early RAP.
• Children with a parent with gastrointestinal problems are more likely to have RAP.
• There is an association with a history of illness in siblings.
• Attention deficit hyperactivity disorder (ADHD) is associated with a twofold increase in RAP.
• Being bullied is associated with increased health complaints in children, including RAP[.
• Child abuse, including sexual abuse and neglect, may present with RAP. Unexplained abdominal symptoms are common in abused children.
• It may be relevant that research suggests a high prevalence of recalled history of pediatric sexual abuse in adults with functional gastrointestinal illness.

Presentations of recurrent abdominal pain in children

Several symptom groups are seen in childhood RAP, allowing classification into commonly occurring presentations. The Rome criteria define these as

• Childhood IBS (this accounts for over 70% of all pediatric RAP).
• Functional dyspepsia.
• Postprandial distress syndrome.
• Epigastric pain syndrome.
• Abdominal migraine.
• Functional abdominal pain (FAP).
• FAP syndrome.

Pediatric IBS

At least four times a month for at least two months:

• Abdominal pain which, at least 25% of the time, is:
  • Improved with defecation
  • Onset is associated with a change in stool frequency or form.
• After an appropriate medical evaluation, the symptoms cannot be attributed to another medical condition.

Child IBS patients are generally classified into three types: constipation-predominant, diarrhea-predominant, and mixed or alternating type, according to the predominant stool type associated with abdominal pain episodes. 

Children with IBS often experience a sense of incomplete evacuation after defecation and sit on the toilet for a long time.

Functional dyspepsia

Functional dyspepsia is a medical condition that affects the digestive system, specifically the stomach. It is characterized by symptoms such as stomach pain, bloating, and nausea, not caused by structural abnormalities or underlying diseases.

Functional dyspepsia can also affect children, although it is more common in adults. In children, the symptoms of functional dyspepsia may be similar to those in adults but can also include vomiting, regurgitation, and difficulty gaining weight.

The exact cause of functional dyspepsia in children is unknown, but it is believed to be related to problems with how the stomach and intestines function. 

Treatment for functional dyspepsia in children typically involves dietary changes, such as avoiding spicy or fatty foods and medication to relieve symptoms.

Postprandial pain syndrome

For at least two months:

• Troublesome postprandial fullness, occurring after ordinary-sized meals, several times per week; and
• Early satiation prevents finishing a regular meal several times per week.

Other symptoms may include:

• Upper abdominal bloating or postprandial nausea.
• Excessive belching.
• Epigastric pain syndrome may co-exist.

Epigastric pain syndrome

At least four times a month for at least two months:

• Intermittent pain or burning localized to the epigastrium of at least moderate severity:
• Pain is not generalized or localized to other areas.
• Is not relieved by defecation or passage of flatus.
• Does not fulfill criteria for biliary pain.

Other symptoms may include:

• Epigastric pain of a burning quality without a retrosternal component.
• Pain induced or relieved by ingesting a meal also occurs while fasting.
• Postprandial distress syndrome may co-exist.

Abdominal migraine

At least twice in the preceding 12 months, all of the following:

• Paroxysmal episodes of intense, acute periumbilical pain lasting at least an hour.
• Intervening periods of normal health, lasting weeks to months.
• The pain interferes with normal activities.
• The pain is associated with two or more anorexia, nausea, vomiting, headache, photophobia, and pallor.
• After an appropriate medical evaluation, the symptoms cannot be attributed to another medical condition.

Functional abdominal pain (FAP)

At least four times a month for at least two months:

• Episodic or continuous abdominal pain.
• Insufficient criteria for other functional gastrointestinal disorders.
• After an appropriate medical evaluation, the symptoms cannot be attributed to another medical condition.

FAP syndrome

At least four times a month for at least two months:

• Impairment of normal activities.
• FAP in at least 25% of episodes.
• Somatic symptoms such as headache, limb pain, or difficulty sleeping.

Presentations suggestive of organic disease

The presence of alarm symptoms or signs increases the likelihood of organic disease and should prompt further investigation. 

Without alarm symptoms, diagnostic studies are unlikely to detect organic disease, although children should be reviewed. 

It is important, as always, to re-evaluate at review. Occasionally, alarm symptoms may not be present at the first presentation but appear later.

Alarm features in RAP

Features suggestive of underlying organic pathology include

• Involuntary weight loss.
• Falling off growth centiles.
• Gastrointestinal blood loss.
• Significant vomiting.
• Chronic severe diarrhea.
• Unexplained fever.
• Persistent right upper or right lower quadrant pain.
• Family history of inflammatory bowel disease.
• Abnormal physical signs include pallor, jaundice, guarding, rebound tenderness, altered bowel sounds, or a palpable mass.
• Joint inflammation.
• Oral and/or perianal lesions.
• Skin rashes.
• Delayed puberty.
• Remember to be alert to any features suggestive of child abuse, including sexual abuse and neglect.

Typical Clinical features of organic versus non-organic causes of RAP

History

The history should be aimed at assessing the problem and its impact on the child and their family, looking for the presence of alarm symptoms, and identifying factors that may be contributing to the pain. 

The history should focus on the following:

• Site of pain. The history of children can be difficult. There may be difficulties describing the pain and localizing it once the pain has passed.
• Quality and nature of pain.
• Timing and duration of pain.
• Whether the pain is relieved by defecation or not.
• Associated symptoms (e.g., headache, tiredness, belching, altered bowel habit).
• The severity of the pain (pain scales can sometimes be helpful, although they can also be misleading).
• Effect of the pain on school attendance, physical activity, and daily living.
• Beliefs and concerns of the child and parent regarding the source and meaning of the pain and their expectations of the physician.
• Diet, including any known or suspected allergies or intolerances.
• Family history of bowel disorders.
• Focus on
  • Gastrointestinal symptoms, including bowel habits.
  • Genitourinary symptoms.
  • Past medical history. It is important to review any past illnesses, hospital admissions, and relevant perinatal and neonatal history.

Examination

Careful examination is helpful in excluding organic disease but also in showing patients that their condition is being thoroughly evaluated.

• Plot height and weight on a growth chart (documented significant weight loss is a red flag sign).
• Check for signs of anemia, jaundice, mouth ulcers, skin rash, and arthritis.
• Ask the child to point with one finger to where the pain is worse and is most frequently felt. In IBS, this is most often around the umbilicus.
• Inspect the abdomen for scars or distension and palpate for masses.
• Check perianal appearance: prominent perianal skin tags or fistulae suggest Crohn’s disease.
• Palpate for organomegaly, tenderness, and/or abdominal mass.

Typically, there is vague tenderness without guarding or rigidity, and bowel sounds will be normal. It can be helpful to discuss the reassurance of normal findings.

Investigations

The possibility of non-organic causes needs to be raised early in the consultation. Commencing investigations before discussing this makes subsequent acceptance of a non-organic diagnosis difficult, as the doctor may appear to have run out of ideas.

Some literature suggests that in the absence of a red flag or alarm symptoms, no investigations are justified. Others point out that, given that both coeliac disease and giardiasis may cause unexplained abdominal symptoms without red flag symptoms, and both are relatively common in the US, some investigations are needed.

A pragmatic approach to primary care investigation is to:

• Offer reassurance and explanation regarding the likely mechanism of pain.
• Explain that you would like to arrange a blood and stool test to rule out coeliac disease and any other signs of inflammation that might change this view.
• Check FBC, inflammatory markers, and anti-endomysial antibodies.
• Stool sample for giardia. Depending on your global location, you may wish to add an examination for cysts, ova, and parasites.
• Consider urine microscopy to rule out recurrent urinary infections.

Further blood and stool tests and further imaging are not indicated without red flag symptoms. Suppose the child is afraid of blood tests and has no alarm symptoms, and coeliac disease is considered excluded by the history. 

In that case, it is worth remembering that blood tests have extremely low yields in terms of positive results.

FBC and ESR have very low positive yield in well children. If a coeliac screen is also needed, checking FBC and ESR on the same sample seems pragmatic when the child has bravely borne the test. 

Other blood tests, ultrasound, computerized tomography examination, and endoscopy provide no benefit in investigating RAP without alarm symptoms.

Differential diagnosis

The list of diagnoses of abdominal pain in children and adolescents includes common, uncommon, and rare conditions. There are also many conditions where RAP might occur, but it would not be the predominant symptom.

The most likely differential diagnoses in a child who is otherwise well are:

• Constipation (which may also co-exist with IBS).
• Coeliac disease.
• Lactose intolerance (including transient symptoms after gastroenteritis).
• Giardiasis. Symptoms closely mimic IBS
• Mesenteric adenitis.
• Urinary tract infections.
• Mittelschmerz.
• Period pain.

Other differential diagnoses which may need to be considered but which would typically raise red flags in the history and examination:

• Intussusception (uncommon over 18 months of age, but a medical emergency).
• Gastro-oesophageal reflux disease.
• Crohn’s disease.
• Ulcerative colitis.
• Urolithiasis.
• Pancreatitis.
• Meckel’s diverticulum.
• Peptic ulcer disease.
• Wilms’ tumor (peaks at 3-4 years of age; rare at age above 10 years).
• Helminth infestation (globally significant; rare as a UK cause).
• Childhood abdominal sarcomas.
• Pregnancy.
• Sexually transmitted infection.

There is a long list of conditions in which RAP might feature but not predominate or be the sole feature, including:

• Sickle cell disease.
• Familial Mediterranean fever.
• Porphyria.
• Lead poisoning.
• Chronic infection – e.g., tuberculosis.

Management

The most important therapeutic step is to explain the diagnosis, explain strategies to cope with stress and provide reassurance that there is no serious underlying disease.

Most children with RAP are successfully managed in primary care, although follow-up will be required, and continuity of care is highly valued. 

Management of functional abdominal pain focuses on improving quality of life, reducing parent and child concerns about the seriousness of the condition, and reducing the disability associated with pain.

Although evidence is lacking for most pharmacological treatments of functional abdominal pain, psychological therapies such as cognitive behavioral therapy and hypnotherapy have been shown to be beneficial.

Initial discussion

Establishing empathy is essential. Doctors should adopt a positive approach. Once the diagnosis is made, explaining that there is no serious underlying disease is important. 

Parents and children must not feel discredited or dismissed. Specific worries about potential causes must be addressed.

Explaining symptoms

An explanation of symptoms is essential. Many doctors find functional disorders difficult as they feel they challenge patients’ health beliefs. 

However, children and parents are generally receptive to clear, informed explanations. They will be relieved that nothing serious underlies the problems and that you have met the problem before – particularly if you have positive suggestions and a plan for follow-up.

It can be helpful to equate functional pain with parents’ personal experience, such as the understanding that people get headaches when worried, become nauseated when given bad news, or develop loose stools when anxious. 

This helps people accept that stress causes physical pain and is a normal response.

Helping parents respond

Parents should be advised to reduce concerned responses to their child’s pain, focusing on the distraction instead. Doctors, parents, and teachers should identify (and remove) things that reinforce me symptoms (such as time off school with access to TV and treats or being excused from homework tasks).

Managing school absence

The child should be strongly encouraged not to allow pain to lead to removal from normal activities. Children should attend school irrespective of pain. This can be difficult at first; however, progress is often rapid. 

The school may need reassurance with a letter from the doctor explaining the pain is non-organic but acknowledging its genuine nature. Pain during class is managed by a continuation of the usual routine, not by removal to a sick room.

Gradual re-introduction of a child to school (for example, half-days) is not advised as it can paradoxically reinforce symptoms by focusing on sickness rather than wellness. The child’s pain can be acknowledged but should not be focused upon.

Avoid excessive investigations

Excessive investigations, ambiguous or contradictory advice, lack of continuity, and failure to accept pain as genuine can result in poor outcomes. Patients respond better to explanations for functional pain that make sense, remove blame from them and generate ideas about the management of symptoms. 

In a study, parents stated that they, as well as their children, needed guidance from professionals to understand the complex pain situation.

Therapeutic interventions

The following therapeutic interventions have been used in children with IBS where explanation and return to normal activities have not been successful or possible. 

However, with the possible exception of dietary advice and probiotics, these are not interventions for the first appointment but are reserved for difficult-to-manage cases with intrusive symptoms.

Dietary interventions

• There is some evidence suggesting that probiotics may be effective in improving pain in children with RAP.
• There is no convincing evidence that fiber-based interventions improve pain in children with RAP.
• Further high-quality evidence is required before fiber supplements and low-FODMAP diets can be recommended.

Drug treatment 

There is currently no convincing evidence to support using drugs to treat RAP in children. Medication to alleviate symptoms should be limited to those children who have symptoms impacting their quality of life and have not responded to simple management.

For abdominal migraine, non-pharmacological treatment options include avoidance of triggers, behavioral therapy, and dietary modifications. Drug therapy should be considered only if symptoms are refractory to these primary interventions.

Biopsychosocial therapies

• Hypnotherapy: has a beneficial effect in children with IBS, which persists for at least five years after cessation of therapy. It is thought to reduce visceral hyperalgesia and colonic contractions and improve the patient’s negative thoughts about their condition. A systemic review found statistically significant improvement in abdominal pain scores.
• Cognitive behavioral therapy: may be effective for children with RAP, although the need for multiple sessions limits practicality.
• Yoga exercises: have been found to be effective in children with RAP, resulting in a significant reduction of pain intensity and frequency.
• Acupuncture: may relieve pain. However, there is conflicting evidence for its effectiveness in RAP.

Alternative healthcare

Alternative medicine flourishes around functional bowel disorders, as in many others where medicine does not offer simple answers.

A range of alternative theories of pathophysiology exist online, many allowing patients to purchase non-evidence-based allergy tests. These may lead to (sometimes restrictive) exclusion diets.

These tests and consultations may be expensive, and whilst, as doctors, we encourage patients to be empowered, gather information from many sources, and seek solutions that work for them, it is also important to advise them in areas where the quality of the evidence may be being misrepresented.

In the case of children, there are two particular issues:

• Particular caution is needed regarding exclusion diets in children, as a balanced diet with adequate calorie intake is crucial for growth and development, bone and muscle health, energy and fitness, learning, and general well-being.
• Focusing on simple ’causes’ of RAP may feel easier and more understandable at first, but this can be counter-productive. If/when the restrictive diet is not tolerable or does not prevent symptoms, the child’s sense of being failed may make solving the problem more difficult.

The doctor should find out whether patients with functional bowel disorders have explored options in alternative medicine and offer appropriate and objective advice and support.

Prognosis

• Some children with RAP will continue to have intermittent or constant IBS.
• Children are more likely to have recovered at follow-up if their parents accept a psychological cause for symptoms.

Possible risk factors for chronicity:

• Presentation under the age of 6 years.
• History of more than six months before presentation.
• Parental functional problems, stressful life events, and sexual abuse are all associated with the persistence of FAP.
• Anxiety, depression, and the severity of pain are not related to persistence.

Summary

Pediatric RAP is a significant and prevalent problem, which can have a massive impact on a child’s well-being, hitting school attendance, mood, and perception of their own health and fitness. 

If an over-prolonged search for organic disease is pursued at the expense of thorough assessment, engagement, explanation, and review, the problem can become increasingly difficult for parents, patients, and doctors.

However, with careful history and examination, clear explanation and follow-up, and a commitment from parent and child to stop the condition limiting normal activities, good results are obtained for children without a referral, drugs, or extensive testing.

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