What are the recommendations of the ACG guidelines for the diagnosis and treatment of irritable bowel syndrome (IBS)?

This article is compiled and organized by Yimaitong, please do not reprint without authorization
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Irritable bowel syndrome (IBS) is a highly prevalent chronic disease that severely reduces the quality of life of patients
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 The diagnosis and management of IBS has come a long way in recent years, prompting the American College of Gastroenterology (ACG) to develop this first guideline
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 Through a comprehensive literature search, the ACG answered 25 of the most clinically interesting questions related to IBS, with the first 9 questions focusing on diagnosis and examination, and the last 16 questions focusing on its treatment modalities
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The development of this guideline is based on the Delphi method, and the main statements are as follows: 1.
Serological testing is recommended for IBS patients and patients with diarrhea symptoms to exclude celiac disease
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(Strong recommendation, moderate quality of evidence) 2.
It is recommended to check fecal calprotectin (or fecal lactoferrin) and C-reactive protein in suspected IBS patients without alarming signs and in patients with diarrhea to exclude inflammatory bowel disease
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(Check fecal calprotectin, C-reactive protein: strong recommendation, moderate quality of evidence) (Check fecal lactoferrin, strong recommendation, low quality of evidence) 3.
Routine fecal intestinal pathogen testing is not recommended for all IBS patients
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(Conditional recommendation, low quality of evidence) 4.
Routine colonoscopy is not recommended for patients under the age of 45 with IBS symptoms and no alarming signs
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(Conditional recommendation, low quality of evidence) 5.
Recommend an aggressive diagnostic strategy for patients with IBS symptoms, not just diagnosis by excluding other diseases, to shorten the time to start correct treatment
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(Consensus recommendation, this item cannot be assessed using a scoring method) 6.
It is recommended to adopt an aggressive diagnostic strategy for patients with IBS symptoms, not just diagnosis by excluding other diseases, to improve cost-effectiveness
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(Strong recommendation, high quality of evidence) 7.
It is recommended that patients be classified according to well-defined IBS subtypes to improve treatment
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(Consensus recommendation, this item cannot be assessed using a scoring method) 8.
Food allergy and food sensitivity testing is not recommended for all IBS patients unless the patient has symptoms related to food allergy
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(Consensus recommendation, no scoring method can be used to evaluate this item) 9.
It is recommended to perform anorectal physiological function test for IBS patients with symptoms suggestive of pelvic floor muscle dysfunction and/or refractory constipation who are ineffective to conventional drug therapy
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Anorectal dysfunction can occur in all subtypes of IBS (IBS-D, IBS-C, and IBS-M), with an estimated prevalence of up to 40%
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Due to the lack of clear guidelines, routine anorectal manometry (ARM) and/or balloon expulsion test (BET) diagnostic tests are not performed in most patients with IBS
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In symptomatic patients, the likelihood of pelvic floor dysfunction increased (sensitivity 75%, specificity 87%) if careful rectal examination did not reveal significant anorectal structural abnormalities
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Figure 1 illustrates the physiology of normal bowel movements and dyssynergic defecation (DD)
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Figure 1 Normal bowel movements and DD
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 Although anorectal physiology alone may not distinguish DD from IBS, it can identify obvious abnormalities that respond well to biofeedback therapy
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Considering the high prevalence of pelvic floor dysfunction among all IBS subtypes, we recommend starting with standard therapy for abdominal pain and bowel habits in IBS
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For patients with IBS refractory to conventional therapy with dyssynchrony detected on rectal examination or pelvic floor symptoms, anorectal physiology testing using ARM, BET, and/or defecation angiography is recommended to identify patients who are responsive to biofeedback therapy
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This suggestion is further supported by the positive response to biofeedback therapy in IBS patients with abdominal pain and bloating
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(Consensus recommendation, this article cannot be assessed using a scoring method) 10.
A limited trial of a low-FODMAP diet in IBS patients is recommended to improve overall IBS symptoms
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(Conditional recommendation, very low quality of evidence) Elimination of fermentable oligosaccharides, disaccharides, monosaccharides, and polyols from the diet (FODMAP) is a treatment option for people with IBS
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After FODMAP enters the digestive tract, it leads to increased gastrointestinal water secretion and colonic fermentation, resulting in the production of short-chain fatty acids and gas, which can cause bloating in IBS patients and trigger eating-related symptoms in IBS patients
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 Most trials have reported benefits of a low-FODMAP diet on some IBS symptoms, particularly abdominal pain and bloating
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Overall, a low-FODMAP diet appears to be safe and does not lead to serious adverse events, but chronic overrestriction of FODMAP may lead to micronutrient deficiencies
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 At the same time, given the time and resources expended in counseling patients during the three phases of the low-FODMAP diet, it is difficult to correctly guide low-FODMAP dieters to strictly follow the dietary requirements
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 (Phase 1: Eat low FODMAP foods only; Phase 2: Monitor patient's symptoms while reintroducing food; Phase 3: Take a personalized diet - avoid foods that trigger symptoms) 11.
Soluble fiber is recommended (Insoluble fiber is not recommended) for overall IBS symptoms
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(strong recommendation, moderate quality of evidence) 12.
Antispasmodics are not recommended for overall IBS symptoms
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(Conditional recommendation, low quality of evidence) 13.
Peppermint is recommended for relief of overall IBS symptoms
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(conditional recommendation, low quality of evidence) 14.
Probiotics are not recommended for overall IBS symptoms
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(Conditional recommendation, very low quality of evidence) 15.
The use of PEG products to relieve overall IBS symptoms in patients with IBS-C is not recommended
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(conditional recommendation, low quality of evidence) 16.
Recommend chloride channel activators to treat overall IBS-C symptoms
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 (Strong recommendation, moderate quality of evidence) 17.
A guanylate cyclase agonist is recommended for overall IBS-C symptoms
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 (Strong recommendation, high quality of evidence) 18.
The 5-HT4 agonist tegaserod is recommended for the treatment of IBS-C female patients under 65 years of age, with cardiovascular risk factors ≤1, and poor response to secretagogues
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(Strong/conditional recommendation, low quality of evidence) Tegaserod is the only FDA-approved 5-HT4 receptor agonist for the treatment of IBS-C in adult women younger than 65 1 patient with cardiovascular risk factors
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 19.
Bile acid sequestrants are not recommended for overall IBS-D symptoms
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(Conditional recommendation, very low quality of evidence) 20.
Rifaximin is recommended for overall IBS-D symptoms
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(Strong recommendation, moderate quality of evidence) 21.
We recommend alosetron for relief of overall IBS-D symptoms in women with severe symptoms who have failed conventional therapy
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(Conditional recommendation, low quality of evidence) 22.
Mixed opioid agonist-antagonists are recommended for the treatment of IBS-D symptoms
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(Conditional recommendation, moderate quality of evidence) 23.
Tricyclic antidepressants are recommended for overall symptoms of IBS
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(Strong recommendation, moderate quality of evidence) 24.
Gut-directed psychotherapy is recommended for overall IBS symptoms
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(Conditional recommendation, very low quality of evidence) 25.
Based on the available evidence, fecal transplantation is not recommended for overall IBS symptoms
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(Strong recommendation, very low quality of evidence) Yimaitong compiled from: Lacy BE, Pimentel M, Brenner DM, et al.
ACG clinical guideline: management of irritable bowel syndrome[J].
Official journal of the American College of Gastroenterology| ACG, 2021, 116(1): 17-44.