Evaluation of chronic abdominal pain

Chronic abdominal pain is defined as continuous or intermittent abdominal discomfort lasting for at least 3 months.[1]Treede RD, Rief W, Barke A, et al. Chronic pain as a symptom or a disease: the IASP classification of chronic pain for the International Classification of Diseases (ICD-11). Pain. 2019 Jan;160(1):19-27. http://www.ncbi.nlm.nih.gov/pubmed/30586067?tool=bestpractice.com Pain may arise from any system, including the genitourinary, gastrointestinal, and gynecologic tracts. The etiology of chronic abdominal pain is so wide that only the more common causes can be covered here. A clear relationship with an anatomic structure or underlying process may not always be present. 

Diagnosis and management of patients with chronic abdominal pain is often challenging and can be a frustrating experience for both physicians and patients. Factors that contribute to this include poor sensitivity of the history and physical exam, a broad differential diagnosis that crosses several specialties, and an often negative diagnostic workup.

Classification

Chronic abdominal pain is divided into organic and functional etiologies.[2]Yarger E, Sandberg K. Updates in diagnosis and management of chronic abdominal pain. Curr Probl Pediatr Adolesc Health Care. 2020 Aug;50(8):100840. https://www.sciencedirect.com/science/article/abs/pii/S1538544220301061?via%3Dihub http://www.ncbi.nlm.nih.gov/pubmed/32859509?tool=bestpractice.com ​ Organic etiologies have a clear anatomic, physiologic, or metabolic cause. Chronic abdominal pain without clear source, in spite of a thorough diagnostic evaluation, is usually termed a functional disorder.[3]Sabo CM, Grad S, Dumitrascu DL. Chronic abdominal pain in general practice. Dig Dis. 2021;39(6):606-14. https://karger.com/ddi/article/39/6/606/822861/Chronic-Abdominal-Pain-in-General-Practice http://www.ncbi.nlm.nih.gov/pubmed/33631744?tool=bestpractice.com ​ Functional abdominal pain is thought to arise from multifactorial visceral hypersensitivity and dysmotility and altered function of the brain-gut axis.[4]Korterink J, Devanarayana NM, Rajindrajith S, et al. Childhood functional abdominal pain: mechanisms and management. Nat Rev Gastroenterol Hepatol. 2015 Mar;12(3):159-71. http://www.ncbi.nlm.nih.gov/pubmed/25666642?tool=bestpractice.com

Chronic abdominal pain is less likely to reveal underlying organic pathology than acute abdominal pain. Acute abdominal pain often indicates a sudden physiologic change such as an obstructed or perforated hollow organ, infection, inflammation, or a sudden ischemic event.

Epidemiology

Chronic abdominal pain is a common complaint in primary care and subspecialty clinics.[3]Sabo CM, Grad S, Dumitrascu DL. Chronic abdominal pain in general practice. Dig Dis. 2021;39(6):606-14. https://karger.com/ddi/article/39/6/606/822861/Chronic-Abdominal-Pain-in-General-Practice http://www.ncbi.nlm.nih.gov/pubmed/33631744?tool=bestpractice.com The incidence of unspecified abdominal pain is 22.3 per 1000 person-years.[5]Wallander MA, Johansson S, Ruigomez A, et al. Unspecified abdominal pain in primary care: the role of gastrointestinal morbidity. Int J Clin Pract. 2007 Oct;61(10):1663-70. http://www.ncbi.nlm.nih.gov/pubmed/17681003?tool=bestpractice.com In an international meta-analysis, the primary care consultation prevalence for abdominal pain is 2.8%.[6]Viniol A, Keunecke C, Biroga T, et al. Studies of the symptom abdominal pain--a systematic review and meta-analysis. Fam Pract. 2014 Oct;31(5):517-29. https://academic.oup.com/fampra/article/31/5/517/537129?login=false http://www.ncbi.nlm.nih.gov/pubmed/24987023?tool=bestpractice.com ​ More than half of all patients presenting with the symptom of abdominal pain do not have a causative diagnosis.[6]Viniol A, Keunecke C, Biroga T, et al. Studies of the symptom abdominal pain--a systematic review and meta-analysis. Fam Pract. 2014 Oct;31(5):517-29. https://academic.oup.com/fampra/article/31/5/517/537129?login=false http://www.ncbi.nlm.nih.gov/pubmed/24987023?tool=bestpractice.com [7]Freeman TR, Stewart M, Léger D, et al. Natural history of abdominal pain in family practice: longitudinal study of electronic medical record data in southwestern Ontario. Can Fam Physician. 2023 May;69(5):341-51. https://www.cfp.ca/content/69/5/341.long http://www.ncbi.nlm.nih.gov/pubmed/37172994?tool=bestpractice.com [8]Price SJ, Gibson N, Hamilton WT, et al. Diagnoses after newly recorded abdominal pain in primary care: observational cohort study. Br J Gen Pract. 2022 Aug;72(721):e564-70. https://pubmed.ncbi.nlm.nih.gov/35760565 http://www.ncbi.nlm.nih.gov/pubmed/35760565?tool=bestpractice.com ​​​​​​​​ One cross-sectional survey of US adults reported a prevalence of abdominal pain in 21.8% in the general population.[9]Sandler RS, Stewart WF, Liberman JN, et al. Abdominal pain, bloating, and diarrhea in the United States: prevalence and impact. Dig Dis Sci. 2000 Jun;45(6):1166-71. http://www.ncbi.nlm.nih.gov/pubmed/10877233?tool=bestpractice.com Women are more likely than men to report chronic abdominal pain.[3]Sabo CM, Grad S, Dumitrascu DL. Chronic abdominal pain in general practice. Dig Dis. 2021;39(6):606-14. https://karger.com/ddi/article/39/6/606/822861/Chronic-Abdominal-Pain-in-General-Practice http://www.ncbi.nlm.nih.gov/pubmed/33631744?tool=bestpractice.com In the US, abdominal pain is the most common symptom and diagnosis of gastrointestinal diseases to prompt a healthcare visit.​[10]Peery AF, Crockett SD, Murphy CC, et al. Burden and cost of gastrointestinal, liver, and pancreatic diseases in the United States: update 2021. Gastroenterology. 2022 Feb;162(2):621-44. https://www.gastrojournal.org/article/S0016-5085(21)03655-6/fulltext?referrer=https%3A%2F%2Fpubmed.ncbi.nlm.nih.gov%2F http://www.ncbi.nlm.nih.gov/pubmed/34678215?tool=bestpractice.com ​ ​However, in a US survey of adults with a history of abdominal pain, almost 40% did not seek medical care for their symptoms.[11]Lakhoo K, Almario CV, Khalil C, et al. Prevalence and characteristics of abdominal pain in the United States. Clin Gastroenterol Hepatol. 2021 Sep;19(9):1864-72.e5. https://www.cghjournal.org/article/S1542-3565(20)30929-0/fulltext http://www.ncbi.nlm.nih.gov/pubmed/32629129?tool=bestpractice.com

Worldwide, the prevalence of functional gastrointestinal disorders (FGID, also known as disorders of gut-brain interaction) in adults is over 40%.[12]Sperber AD, Bangdiwala SI, Drossman DA, et al. Worldwide prevalence and burden of functional gastrointestinal disorders, results of Rome Foundation Global Study. Gastroenterology. 2021 Jan;160(1):99-114.e3. https://www.gastrojournal.org/article/S0016-5085(20)30487-X/fulltext?referrer=https%3A%2F%2Fpubmed.ncbi.nlm.nih.gov%2F http://www.ncbi.nlm.nih.gov/pubmed/32294476?tool=bestpractice.com ​ FGID conditions are heterogenous and irritable bowel syndrome and functional dyspepsia are the most common.[12]Sperber AD, Bangdiwala SI, Drossman DA, et al. Worldwide prevalence and burden of functional gastrointestinal disorders, results of Rome Foundation Global Study. Gastroenterology. 2021 Jan;160(1):99-114.e3. https://www.gastrojournal.org/article/S0016-5085(20)30487-X/fulltext?referrer=https%3A%2F%2Fpubmed.ncbi.nlm.nih.gov%2F http://www.ncbi.nlm.nih.gov/pubmed/32294476?tool=bestpractice.com However, the pain associated with these disorders is nonspecific and can resemble or coexist with organic disorders.[13]Colombel JF, Shin A, Gibson PR. AGA clinical practice update on functional gastrointestinal symptoms in patients with inflammatory bowel disease: expert review. Clin Gastroenterol Hepatol. 2019 Feb;17(3):380-90.e1. https://www.cghjournal.org/article/S1542-3565(18)30810-3/fulltext http://www.ncbi.nlm.nih.gov/pubmed/30099108?tool=bestpractice.com ​ A subset of patients with FGID do not respond to first-line therapy and have persistent chronic abdominal pain.[14]Keefer L, Ko CW, Ford AC. AGA clinical practice update on management of chronic gastrointestinal pain in disorders of gut-brain interaction: expert review. Clin Gastroenterol Hepatol. 2021 Dec;19(12):2481-8.e1. https://www.cghjournal.org/article/S1542-3565(21)00717-5/fulltext http://www.ncbi.nlm.nih.gov/pubmed/34229040?tool=bestpractice.com  

The prevalence of chronic abdominal pain in children varies widely (4% to 53%).[15]King S, Chambers CT, Huguet A, et al. The epidemiology of chronic pain in children and adolescents revisited: a systematic review. Pain. 2011 Dec;152(12):2729-38. http://www.ncbi.nlm.nih.gov/pubmed/22078064?tool=bestpractice.com [16]Tutelman PR, Langley CL, Chambers CT, et al. Epidemiology of chronic pain in children and adolescents: a protocol for a systematic review update. BMJ Open. 2021 Feb 16;11(2):e043675. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7888311 http://www.ncbi.nlm.nih.gov/pubmed/33593785?tool=bestpractice.com [17]​World Health Organization. Guidelines on the management of chronic pain in children. Dec 2020 [internet publication]. https://www.who.int/publications/i/item/9789240017870 ​ ​​The prevalence of pediatric functional abdominal pain is 13.5%.[18]Korterink JJ, Diederen K, Benninga MA, et al. Epidemiology of pediatric functional abdominal pain disorders: a meta-analysis. PLoS One. 2015 May 20;10(5):e0126982. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0126982 http://www.ncbi.nlm.nih.gov/pubmed/25992621?tool=bestpractice.com