Irritable bowel syndrome (IBS) is a common condition encountered by pediatric health care providers. The World Gastroenterology Association practice guideline1 recently defined IBS as a functional bowel disorder in which abdominal pain or discomfort is associated with defecation, and common clinical manifestations include a change in bowel habits, bloating, distention, and disordered defecation. This chronic condition leads to frustration among patients and their caregivers, as well as clinicians caring for these patients. This article reviews recent updates on the epidemiology, clinical manifestations, evaluation, and understanding of the pathogenesis and management of this condition.
IBS is far more common, particularly in children, than we may realize. It occurs more commonly in those with relatives who have the disorder and in those of higher socioeconomic status. In a study representing 6,060 twin pairs, concordance for IBS was significantly higher among monozygotic (17.2%) than dizygotic (8.4%) pairs.2 This same study also showed that having a mother or father with IBS was an even stronger predictor than having a twin.2 The prevalence of IBS in school-age children ranges between 4.9% and 5.4% when the Rome III criteria (discussed later in the article) are used for diagnosis.1
The prevalence of IBS tends to be higher in Western countries (∼10%) than in Asian countries (∼5%).3 An epidemiologic study in Italy indicated that the prevalence of IBS in children ages birth to 12 years is 13.9%.3 Among 14- to 17-year old students in Moscow, Russia, the prevalence of IBS was found to be 14% to 24%.3
There is some evidence that the prevalence of IBS subtypes varies among different regions of the world. In parts of Asia, Western Europe, and North America constipation seems to be very common; in Bangladesh and India diarrhea is most common; and in Brazil an alternating type (both constipation and diarrhea occurring in same patient) predominates.1 In developing nations there are reports of association of IBS with prior parasitic infections, such as giardiasis or trichinellosis.1 There is increasing evidence of an association between infection with Campylobacter and IBS.4
IBS has been associated with a history of physical, psychological, and/or sexual abuse during infancy, childhood, or early adult life in studies from North America; these have also been identified as risk factors in studies from other countries.1
Cristofori et al.5 conducted a study of 782 children in Italy with abdominal pain-related disorders, including 270 with IBS, 311 with functional abdominal pain (FAP), and 201 with functional dyspepsia. Blood tests on each patient were performed to see how many children with a gastrointestinal disorder were also affected by celiac disease. Twelve patients with IBS, two patients with functional dyspepsia, and one patient with FAP had laboratory test results indicative of celiac disease. Children with IBS were 4 times more likely to develop celiac disease compared with those affected by other abdominal pain disorders. This would suggest that selective screening for celiac disease is warranted for children with IBS, but not for children with other functional gastrointestinal disorders.5
Despite significant research, to date, no clear pathophysiologic mechanism has been identified for IBS. The underlying mechanism and its clinical presentation vary from patient to patient. There have been several different mechanisms postulated in adults and children, most of which rely on the basic principle that IBS is a state of dysregulation between the brain and the gut. This state of dysregulation occurs within the enteric and central nervous systems, leading to changes in gut sensation, motility, and possible immune system dysfunction.2
A study of 35 children (ages 10 to 17.6 years) who met the criteria for IBS showed that abdominal pain is associated with visceral hypersensitivity and abnormal perception of visceral sensations.2 The pain is likely neurologic in origin and some studies6–8 have shown that this pain affects those with IBS at lower intensity levels when compared with people who do not have IBS. Faure and Wieckowska6 studied children with FAP and IBS compared with controls and those with functional dyspepsia. Using rectal balloon distention with a barostat, they demonstrated that children with FAP and IBS sensed rectal pain at a lower pressure threshold compared with controls and children with dyspepsia. Neuroimaging studies have suggested that IBS could also be associated with an up-regulation of afferent sensitivity to pain.6,9
In a study of 10 children with 10 age-matched controls, fecal short chain fatty acid (SCFA) profile of patients with diarrhea-predominant IBS had lower concentrations of total SCFA, acetate, and propionate and a higher percentage and concentration of n-butyrate.2 Gastrointestinal symptoms in those with diarrhea-predominant IBS may be related to differences in the SCFA production by colonic bacteria.2 Some studies10,11 have reported increased infiltration of the intestine with mast cells in patients with IBS.
Twin studies looking at the contribution of familial and genetic factors to the development of IBS have shown that although genetics does play a role in IBS in children, social learning and maladaptive coping play a major role in the pathophysiology of IBS and its associated disability.12
Walker et al.13 have shown that children with IBS were less confident about their ability to deal with daily stress and were less likely to use coping strategies such as accepting the stressor, reframing its significance, or encouraging themselves.9
A recent study in the United States looked at intestinal microbiomes in stool samples from 22 children with IBS and 22 healthy controls.1 Specific microbiome signatures were associated with pediatric IBS, suggesting an association between gastrointestinal microbes and IBS in children. Campylobacter has been proposed to be associated with IBS. It has been proposed that the low-grade inflammation caused by Campylobacter, which cannot be detected by endoscopy, triggers communication between gut nerves, leading to symptoms of IBS.4
There is no evidence that lactose intolerance is the cause of IBS in the majority of cases, but the symptoms of lactose intolerance such as abdominal pain, distension, and diarrhea mimic those of IBS.12
IBS can be diarrhea predominant or constipation predominant. The diarrhea is nonbloody. IBS is often exacerbated by stressful situations or specific foods. The person may often have bouts of severe pain and their daily quality of life is significantly impaired.
The following subtypes of IBS were identified in the Rome III process: IBS with diarrhea, IBS with constipation, IBS with mixed bowel habits or a cyclic pattern, and unsubtyped IBS. Patients may move from one category to another over time.1,14 Walker et al.15 found that 44.9% of children with recurrent abdominal pain met the pediatric Rome III criteria for IBS and could be classified into one or more of the symptom subtypes defined by the criteria.
Children with IBS frequently miss school, have decreased quality of life, have a higher prevalence of psychiatric conditions (eg, anxiety, depression, and introverted personalities) and socialization problems, and require use of medications.9 Children with IBS frequently have difficulty sleeping.
IBS is a clinical diagnosis, and there is no specific laboratory test available to diagnose it. The most important part of establishing the diagnosis of IBS includes a comprehensive history and physical examination, as routine diagnostic testing is not necessary to make the diagnosis.
The diagnostic criteria for IBS are defined by the Rome III criteria. This is a clinically based criteria that allow the diagnosis of functional gastrointestinal disorders based on the report of symptoms by parents and children. The clinical criteria are (1) abdominal pain or discomfort accompanied by at least two of the following symptoms 25% of the time: a) improvement with defecation, b) onset associated with change in frequency of stools, and c) onset associated with a change in form of stools; and (2) no evidence of inflammatory, anatomic, metabolic, or neoplastic process that explains the symptoms.
Liver and kidney function tests, hydrogen breath test, imaging studies, and endoscopies should be performed based on the child's predominant symptoms, red flag symptoms, initial laboratory results, and degree of lifestyle impairment. If a diagnostic evaluation is to be performed, it is important to let the parents know that the results will likely be normal because there are no laboratory markers specific for establishing the diagnosis of IBS.12
Barium studies and colonoscopies are often performed to rule out other causes of the diarrhea and constipation before the diagnosis of IBS is considered. It is important to screen for red flag symptoms, such as blood in the stools, pallor, and growth deceleration, which are suggestive of organic disease such as Crohn's disease or ulcerative colitis. If these symptoms are present, then hemoglobin, erythrocyte sedimentation rate, C-reactive protein, fecal calprotectin, albumin, and testing for blood in stool would be recommended. A recent systematic review concluded that a negative calprotectin test rules out inflammatory bowel disease, sparing those with IBS from invasive studies such as colonoscopy.12
There are data to suggest that celiac screening in patients with symptoms of IBS is cost effective.12
At this time there is no curative therapy for IBS, so it is managed symptomatically by educating the patients and caregivers, changing diet, and using medications such as laxatives and antidiarrheal or antispasmodic agents.
Management of IBS depends on whether the IBS is constipation predominant or diarrhea predominant. Constipation-predominant IBS can be managed with fiber supplements and changes in diet, such as increasing the amount of fruits and vegetables, along with stool softeners. Diarrhea-predominant IBS can also partially be managed with changes in diet, such as adding yogurt with probiotics or cheese.
There is also evidence that cognitive-behavioral therapy (CBT) can improve pain and disability.16 In one study, reduction of abdominal complaints was greater in patients with IBS who received group CBT than those on a waiting list.17 CBT alters the course of IBS by reducing the effects of central nervous system activity on gut function, by providing patients skills to manage stress, anxiety, and gastrointestinal symptoms, and the emotional impact on living with IBS.7 In a systematic review of three randomized controlled trials, all indicated that both hypnotherapy given by a qualified therapist and hypnotherapy through self-exercise and by audio CD were more effective than standard medical treatment in reducing symptoms in pediatric patients with IBS.16 The goal of treatment should not necessarily be the complete resolution of symptoms, but rather the return to normal life.
Due to the paucity of effective pharmacologic treatments for IBS and the relative safety of probiotics, there have been several clinical trials that support the rationale for the use of probiotics in the treatment of IBS. The trials are not sufficient to support a general recommendation for the use of probiotics in children with IBS, and probiotics should not be used as a single therapy. A meta-analysis of three pediatric studies on the efficacy of lactobacillus GG in the treatment of IBS found that children who received lactobacillus GG supplementation had a significant improvement in pain compared with placebo.12 Further studies are necessary to determine the most effective probiotics species and strains for children with IBS.18
Anticholinergic medications are frequently used to decrease symptoms via inhibition of smooth muscle contraction. Dicyclomine and hyoscyamine are commonly used antispasmodics in children. Peppermint oil has also been found to be efficacious by relaxing the intestinal smooth muscles by blocking calcium channels.12
There is mixed evidence on the use of antidepressants for the treatment of IBS in children. The tricyclic antidepressants (TCAs) and selective serotonin uptake inhibitors (SSRIs) have both been used. The TCA, amitriptyline, has been shown to be beneficial in improving quality of life. No pediatric placebo-controlled trials have been performed using citalopram or other SSRIs, and the US Food and Drug Administration has issued a “black box” warning for increased risk of suicidal ideations in adolescents and children when beginning treatment with SSRIs.12
There have been few trials conducted on the efficacy of fiber supplement for the treatment of IBS symptoms, and the results of the trials have been mixed; therefore, there is no current agreement on the benefit of fiber supplements in children with IBS.12
It is not beneficial to restrict lactose in the diets of children with IBS because lactose intolerance has not been shown to be associated with IBS.12
Costs related to functional bowel disorders are significant, with direct and indirect medical costs of caring for children with IBS being estimated as up to $30 billion annually in the US, making this a significant health care problem.19
IBS is more common, especially among children, than we may realize. It appears that the incidence and prevalence of IBS in children are underestimated. IBS can cause severe impairment in children's quality of life, and these children often suffer from multiple psychosocial disorders. Diagnosis of IBS is clinical, and currently there is no laboratory test that can definitively diagnose IBS. The pathophysiology of IBS remains elusive, and therefore there is lack of effective and specific therapy for IBS. Thus, treatment is symptomatic and the medical costs in caring for a child with IBS can be significant.
- Quigley E, Abdel-Hamid H, Barbara G, et al. A global perspective on irritable bowel syndrome: a consensus statement of the World Gastroenterology Organisation Summit Task Force on Irritable Bowel Syndrome. J Clin Gastroenterol. 2012;46(5):356–366. doi:10.1097/MCG.0b013e318247157c [CrossRef]
- Sandhu BK, Paul SP. Irritable bowel syndrome in children: pathogenesis, diagnosis and evidence based treatment. World J Gastroenterol. 2014;20(20):6013–6023. doi:10.3748/wjg.v20.i20.6013 [CrossRef]
- Dong L, Dingguo L, Xiaoxing X, Hanming L. An epidemiologic study of irritable bowel syndrome in adolescents and children in China: a school-based study. Pediatrics. 2005;116:e393–e396. doi:10.1542/peds.2004-2764 [CrossRef]
- Kliegman R, Stanton B, Schor NF, St. Geme JW, Behrman RE. Nelson Textbook of Pediatrics. 19th ed. Philadelphia, PA: Saunders Elsevier; 2011:969.
- Cristofori F, Fontana C, Magista A, et al. Increased prevalence of celiac disease among pediatric patients with irritable bowel syndrome: a 6-year prospective cohort study. JAMA Pediatr. 2014;168(6):555–560. doi:10.1001/jamapediatrics.2013.4984 [CrossRef]
- Faure C, Wieckowska A. Somatic referral of visceral sensations and rectal sensory threshold for pain in children with functional gastrointestinal disorders. J Pediatr. 2007;150:66–71. doi:10.1016/j.jpeds.2006.08.072 [CrossRef]
- Van Ginkel R, Voskuijl WP, Benninga MA, Taminiau JA, Boeckxstaens GE. Alterations in rectal sensitivity and motility in childhood irritable bowel syndrome. Gastroenterology. 2001;120:31–38. doi:10.1053/gast.2001.20898 [CrossRef]
- Di Lorenzo C, Youssef NN, Sigurdsson L, Scharff L, Griffiths J, Wald A. Visceral hyperalgesia in children with functional abdominal pain. J Pediatr. 2001;139:838–843. doi:10.1067/mpd.2001.118883 [CrossRef]
- McOmber M, Shulman R. Recurrent abdominal pain and irritable bowel syndrome in children. Curr Opin Pediatr. 2007;19(5):581–585. doi:10.1097/MOP.0b013e3282bf6ddc [CrossRef]
- Di Nardo G, Barbara G, Cucchiara S, et al. Neuroimmune interactions at different intestinal sites are related to abdominal pain symptoms in children with IBS. Neurogastroenterol Motil. 2014;26:196–204. doi:10.1111/nmo.12250 [CrossRef]
- O'Sullivan M, Clayton N, Breslin NP, et al. Increased mast cells in the irritable bowel syndrome. Neurogastroenterol Motil. 2000;12:449–457. doi:10.1046/j.1365-2982.2000.00221.x [CrossRef]
- Chogle A, Mintjens S, Saps M. Pediatric IBS: an overview on pathophysiology, diagnosis and treatment. Pediatr Ann. 2014;43(4):e76–e82. doi:10.3928/00904481-20140325-08 [CrossRef]
- Walker LS, Williams SE, Smith CA, et al. Validation of a symptom provocation test for laboratory studies of abdominal pain and discomfort in children and adolescents. J Pediatr Psychol. 2006;31:703–713. doi:10.1093/jpepsy/jsj062 [CrossRef]
- Drossman AD, Dumitrascu DL. Rome III: new standard for functional gastrointestinal disorders. J Gastrointestin Liver Dis. 2006;15:237–241.
- Walker LS, Lipani TA, Greene JW, et al. Recurrent abdominal pain: symptom subtypes based on Rome II criteria for pediatric functional gastrointestinal disorders. J Pediatr Gastroenterol Nutr. 2004;38:187–191. doi:10.1097/00005176-200402000-00016 [CrossRef]
- Rutten J, Reitsma J, Vlieger A, Benninga M. Gut-directed hypnotherapy for functional abdominal pain or irritable bowel syndrome in children: a systematic review. Arch Dis Child. 2013;98:252–257. doi:10.1136/archdischild-2012-302906 [CrossRef]
- Prasko J, Jelenova D, Mihal V. Psychological aspects and psychotherapy of inflammatory bowel disease and irritable bowel syndrome in children. Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub. 2010;154(4):307–314. doi:10.5507/bp.2010.046 [CrossRef]
- Ringel Y, Ringel-Kulka T. The rationale and clinical effectiveness of probiotics in irritable bowel syndrome. J Clin Gastroenterol. 2011;45(3):s145–s148. doi:10.1097/MCG.0b013e31822d32d3 [CrossRef]
- Guandalini S, Dhawan A, Branski D, eds. Textbook of Pediatric Gastroenterology and Nutrition. Philadelphia, PA: CRC Press; 2004:231.