Exploring Diagnosis and Treatment Strategies for Irritable Bowel Syndrome—Commentary
Diagnosing and treating functional GI illnesses can be a challenging undertaking. In fact, functional disorders like irritable bowel syndrome (IBS), in which no objectively measurable structural or physiologic abnormality for the complaint can be found, account for as much as half of referrals to gastroenterologists. It’s frustrating for patients as well, who may be suffering from frequent GI symptoms.
An overview of emerging diagnosis and treatment options coupled with an outline of established best practices will be helpful for general practitioners and gastroenterologists seeking more efficient and beneficial interactions with patients dealing with IBS and other functional GI disorders.
Important change in Rome IV guidelines
In May 2016, the Rome Foundation released the latest update to its criteria for diagnosing functional GI disorders. The Rome IV guidelines came with some notable changes, starting with the definition of functional GI disorders. The updated definition is as follows --
Disorders of gut-brain interaction. These disorders are classified by GI symptoms related to any combination of:
- Motility disturbance
- Visceral hypersensitivity
- Altered mucosal and immune function
- Altered gut microbiota
- Altered central nervous system (CNS) processing
In addition to a definition that puts greater emphasis on different processes that can cause the disorders, the updated guidelines for IBS also removed language related to pain relief from a bowel movement and replaced it with criteria around pain associated with a bowel movement. That’s a key distinction, especially for patients who experience discomfort as they’re going to the bathroom or pain that continues even after they’ve moved their bowels. The Rome IV diagnostic criteria for IBS are:
Recurrent abdominal pain, on average, at least 1 day per week for the last 3 months, associated with 2 or more of the following:
- Related to defecation
- Associated with a change in frequency of stool
- Associated with a change in form (appearance) of stool
With symptom onset at least 6 months before diagnosis.
Considering family history and screening timelines
The red flags that could indicate a condition other than IBS or another functional GI disorder are well established and include fever, weight loss, rectal bleeding vomiting, and old age. Increasingly, physicians are adding family history as a key red flag for colon cancer, inflammatory bowel disease, and celiac disease. Celiac disease, in particular, is five times more common in patients with a family history of the disease.
This emphasis on family history, combined with other factors, have shifted the screening recommendations for colon cancer. For those with a family history of colon cancer (when HPNCC is not a consideration), the American College of Gastroenterology (ACG) recommends beginning colon cancer screening at age 40 or 10 years younger than age at diagnosis of the youngest affected relative. Screening for average-risk persons should still begin at age 50, and for African Americans at age 45, according to the ACG.
A tool for guiding the conversation
Ultimately, diagnosis of IBS will largely consist of a conversation with the patient about symptoms, severity, possible triggers, family history, and other considerations. While most patients are comfortable talking through these things with a doctor, many are uncomfortable talking about their bowel movements or have difficulty describing their stool in terms that will be useful for diagnosis and treatment.
In these cases, the Bristol Stool Chart (see page 1396) can be a valuable tool to make patients more comfortable talking about their bowel movements and more efficiently provide physicians with the information they need to make an accurate diagnosis.
Exploring treatment options with patients
For patients suffering from IBS with constipation (IBS-C) or chronic constipation, linaclotide and lubiprostone are relatively new medications that can be useful.
IBS with diarrhea (IBS-D) is typically treated with an antidiarrheal such as loperamide with the dose titrated to reduce the diarrhea. Rifaximin, which has been used for traveler’s diarrhea for a long time, was recently approved for IBS-D and has been shown to improve bloating, abdominal pain, and stool consistency. Patients are given a two-week course of treatment and, if needed, they have responded well to a second course in clinical trials. Eluxadoline has also been shown to be effective in treating IBS-D, but it’s important to note it has a number of contraindications including patients who have had their gall bladder removed, have a history of pancreatitis or other pancreas problems, severe liver impairment, or drink alcohol heavily.
Alternative forms of treatment
As patients look toward more natural and holistic solutions to ongoing health problems, physicians will get more questions about other forms of treatment. Because probiotics are not regulated by the FDA and have so many different formulations, it’s often difficult to determine their effectiveness, even if patients anecdotally report a decrease in symptoms.
Peppermint oil has been shown to be effective in relieving IBS symptoms. Many patients may also ask about changes in diet as a way to alleviate IBS symptoms focused primarily on gluten-free and low-FODMAP diets.
As more research into the effectiveness of these treatment options is published, along with a growing understanding of the gut microbiome in general, it will be exciting to watch how approaches to helping patients relieve pain from IBS and other functional GI disorders evolve.