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American College of Gastroenterology Guidelines for Treating IBS

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By Editorial Team

4 min read

In 2021, the American College of Gastroenterology (ACG) issued recommendations for treating irritable bowel syndrome (IBS). The 22-page guideline focuses on diagnosing and managing the chronic condition.1

The goal of the guidelines is to help people with IBS receive care more quickly and improve their symptoms. The recommendations are based on 25 essential questions relating to IBS identification and therapy.1

Diagnostic testing and screening recommendations

There are 9 diagnostic recommendations in the ACG guideline. They focus on improving and expediting therapy, reducing cost, and ruling out potential diseases. The ACG guidelines recommend:1

  1. Using a positive diagnostic strategy instead of an exclusion strategy for patients with IBS symptoms to improve cost and expedite therapy
  2. Continued categorization based on IBS subtype
  3. Serologic testing (blood tests that look for antibodies in blood) to rule out celiac disease in patients with IBS and diarrhea symptoms
  4. Ruling out inflammatory bowel disease with fecal calprotectin testing (a stool test that detects inflammation in the intestines) in those with IBS-D symptoms
  5. Anorectal physiology testing (tests that check the function of the rectum, anus, and pelvic floor) for those with IBS and pelvic floor disorder symptoms or refractory constipation

What testing is not recommended?

While certain testing can help identify IBS, some tests are not necessary for the majority of people who may have IBS. ACG does not recommend routine:1

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  • Food allergy and sensitivity testing
  • Stool testing for intestinal bacteria, except for those who are at high risk of exposure
  • Colonoscopy for people under the age of 45 if there are no alarming factors

Therapeutic and symptom treatment recommendations

There are 16 recommendations for therapy and IBS symptom treatment. They include suggestions related to diet, supplements, medicine, directed therapy, and procedures.

Diet recommendations

To treat global IBS symptoms, ACG’s diet recommendations include:1

  1. Use soluble, but not insoluble, fiber.
  2. Practice a low-FODMAP diet for a limited time.

Supplement and product recommendations

Some supplements, like peppermint, could be helpful in relieving IBS symptoms. Supplements like probiotics and PEG products are not recommended due to a lack of reliable evidence:1

  • Use peppermint for IBS symptom relief.
  • Probiotics for IBS symptoms not recommended.
  • PEG products for IBS-C symptoms not recommended.

Medicine recommendations

Tricyclic antidepressants (TCAs) such as amitriptyline, desipramine (Norpramin®), and nortriptyline (Pamelor™) are recommended for overall IBS symptom treatment. Drugs like lubiprostone (Amitiza®) and linaclotide (Linzess®) are recommended for IBS-C symptom treatment. Rifaximin (Xifaxan®) and eluxadoline (Viberzi®) can be used to treat IBS-D symptoms.1

The ACG recommends:1

  • Using TCAs to treat IBS symptoms
  • Treating IBS-C symptoms with chloride channel activators, such as lubiprostone
  • Using guanylate cyclase activators to treat IBS-C symptoms, such as Linzess
  • Treating IBS-D symptoms with rifaximin
  • Treating IBS-D symptoms with mixed opioid agonists/antagonists, such as eluxadoline
  • Using alosetron (Lotronex®) for women who did not have relief of severe IBS-D symptoms through conventional therapy
  • Using tegaserod (Zelnorm™) in women younger than 65 who do not respond to secretagogues (drugs such as linaclotide, lubiprostone) and have cardiovascular risk factors

Citing a lack of solid and reliable data, the ACG does not recommend:1

  • Using bile acid sequestrants to treat global IBS-D symptoms, such as the drugs cholestyramine (Questran®) and colestipol (Colestid®)
  • Using antispasmodics for the treatment of global IBS symptoms, such as the drugs dicyclomine (Bentyl®) and hyoscyamine (Levsin®)

Directed therapy and procedure recommendations

The ACG recommends the use of gut-directed psychotherapies to treat global IBS symptoms. These therapies include:1

  • Mindfulness
  • Hypnosis
  • Cognitive therapy
  • Cognitive behavioral therapy (CBT)

Citing a lack of strong evidence, the ACG does not recommend fecal transplants for the treatment of global IBS symptoms.1

What about the Rome IV criteria? Is it any different?

With insight from experts around the world, the Rome IV criteria took more than 5 years to develop. Published in 2016, Rome IV changed how disorders of gut-brain interaction are defined and diagnosed. Rome states symptoms can affect people differently, and disorders of gut-brain interaction are on a spectrum.1,2

Under Rome IV criteria, IBS is classified as recurrent abdominal pain that happens at least once a week and is linked with a change in stool frequency, a change in stool form, or a change in pain related to a bowel movement. Rome IV suggests managing the condition will work best with a biopsychosocial approach, which takes into account factors like:1,2

  • Environment
  • Genetics
  • Culture
  • Personality
  • Stress level
  • Social support
  • Motility
  • Diet

Rome IV was designed more specifically for trials and research, but it can be used to clinically diagnose IBS.1,2

The ACG does not differ from Rome IV’s IBS criteria. In fact, ACG uses Rome IV in its own guideline. The ACG guideline is for use in daily practice, alongside Rome IV as they work in tandem. Similarities and overlaps occur within the 2 documents, most notably approaching treatment through behavioral and psychotherapy.1,3

If you have questions about what the new guidelines and specific drug recommendations mean for your IBS treatment, talk to your doctor.

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