Rome Criteria for IBS: When Is Further Testing Needed?

Does knowing the diagnostic criteria necessarily lead to sound clinical decision-making? Not always. A recent study published in Neurogastroenterology & Motility evaluated medical students from 14 Latin American countries, including Brazil, and found that although most were familiar with the Rome Criteria for disorders of gut-brain interaction (DGBI), many still relied on a diagnosis of exclusion rather than a positive diagnosis. Researchers at the University of Miami in Miami found that this approach persisted even among students who had received formal training in DGBI.

DGBI is characterized by gastrointestinal symptoms related to combinations of altered motility, visceral hypersensitivity, and changes in mucosal function, gut microbiota, or central nervous system processing.

The Rome Criteria are an international consensus framework developed by the Rome Foundation, with inputs from more than 140 experts from 27 countries. They used clinical symptoms to support a positive diagnosis without requiring extensive testing to exclude other diseases.

In an interview with Medscape’s Portuguese edition, study first author Manuel Linares, MD, a researcher at the Miller School of Medicine, University of Miami, Miami, and a resident in the Department of Pediatrics at the University of Pittsburgh Medical Center , Pittsburgh, explained that the main contribution of the Rome Criteria was to shift the diagnostic approach from exclusion to positive diagnosis. However, what does this mean in clinical practice?

Positive vs Exclusion

Irritable bowel syndrome (IBS), a type of DGBI, is a useful example. Traditionally, many physicians have been taught that IBS can be diagnosed only after extensive testing, excluding other possible organic diseases.

Rome Criteria take a different approach. According to Linares and colleagues, IBS can be diagnosed when characteristic symptoms and warning signs are present or absent. “This approach is supported by a large body of evidence showing that extensive routine testing rarely changes the diagnosis in appropriately selected patients,” he said. A positive diagnosis does not mean that the potential warning signs are ignored. “Instead, it means using clinical criteria and warning signs to guide testing in a rational, evidence-based way,” he added.

Although the Rome Criteria are considered the international gold standard for diagnosing and classifying DGBI, studies have shown that specialists still overuse diagnostic testing for conditions such as IBS in clinical practice. A study by researchers at the University of Miami suggests that this exclusion-based approach may develop early during medical training.

The Rome IV Criteria cover six major groups of DGBI in adults, each defined by characteristic symptoms:

• Esophageal disorders: chest pain, heartburn, globus sensation, and difficulty swallowing
• Gastroduodenal disorders: nausea, vomiting, excessive belching, early satiety, and epigastric pain
• Bowel disorders include abdominal pain, constipation, diarrhea, and abdominal bloating
• Centrally mediated abdominal pain disorders: chronic, continuous abdominal pain without an identified structural cause
• Gallbladder and sphincter of Oddi disorders: right upper quadrant or epigastric pain without a structural cause
• Anorectal disorders included fecal incontinence, rectal pain, and difficulty defecating

Study Findings

In a multicenter cross-sectional study, Linares and colleagues evaluated 238 medical students from 45 universities across Latin America. Sixty percent of the universities were public and 40% were private. The students had a mean age of 24.3 years, and all were in the clinical phase of medical school. The 14 participating countries were Argentina, Bolivia, Brazil, Chile, Colombia, Cuba, the Dominican Republic, Ecuador, Honduras, Mexico, Nicaragua, Peru, Uruguay, and Venezuela.

Using a structured questionnaire, the researchers assessed students’ exposure to DGBI education, knowledge of diagnostic principles based on the Rome Criteria, recognition of warning signs, and diagnostic decision-making using standardized clinical vignettes.

Overall, 74% of the participants had received instruction on DGBI and 69% had heard of the Rome Criteria. Despite this prior knowledge, 70% of the students ordered initial diagnostic tests when presented with a clinical vignette describing an adult with IBS who met the Rome IV criteria and had no warning signs. Testing increased as symptom severity increased and was still requested by 53% of the students, even when laboratory results were normal. Approximately one third of the participants incorrectly classified functional symptoms as warning signs.

Warning signs in IBS include gastrointestinal bleeding, unintentional weight loss, fever, nocturnal diarrhea, and family history of serious gastrointestinal disease. None of these features were present in the clinical vignette. Linares noted that, according to current guidelines, the appropriate approach would be to make a positive diagnosis of IBS, provide information and reassurance, discuss treatment options, and arrange follow-up rather than proceed with increasingly extensive testing.

One of the study’s notable findings was that many students correctly recognized the presentation as likely functional but still felt compelled to order diagnostic tests. “This suggests that diagnostic behavior is not always driven by knowledge of the diagnostic criteria alone. Factors such as uncertainty, fear of missing a disease, and the culture of medical training may also play important roles.” Linares said.

The study showed that theoretical knowledge and clinical decision-making were related but not equivalent. “Students with greater theoretical knowledge were less likely to order unnecessary tests, but testing remained common even among those who understood the principles of the Rome Criteria,” he said.

Linares suggested that medical training often emphasizes the identification of rare but serious diseases and rewards extensive investigation. “Students may learn the Rome Criteria in the classroom but receive less training on how to apply these principles when faced with uncertainty in clinical practice,” he said.

Improving this pattern will likely require more than teaching the criteria alone, as Linares said. “Educational strategies should focus on clinical reasoning, including case-based learning, discussion of diagnostic uncertainty, recognition of warning signs, and training on when testing is and is not indicated. Students need opportunities to practice making positive diagnoses with confidence rather than treating every functional presentation as a diagnosis that must first be established by exclusion,” he said.

Medical Perspective

Speaking with Medscape’s Portuguese edition, Dan Linetzky Waitzberg, MD, PhD, from the Laboratory of Nutrition and Metabolic Surgery, Department of Gastroenterology, Faculty of Medicine, University of Sao Paulo, São Paulo, Brazil, discussed the role of the Rome Criteria in diagnosing DGBI. Waitzberg, who was not involved in the study, noted that the criteria are the main international consensus system for DGBI diagnosis. The Rome Foundation developed criteria with input from more than 140 experts from 27 countries.

Beyond changing the diagnostic approach, the Rome Criteria also have scientific importance because they standardize research populations, allowing comparisons across global and regional studies.

In Brazil, the Rome Criteria are used as a reference by major gastroenterology societies and residency programs and can be considered the de facto standard for diagnosing these disorders. However, Waitzberg noted that their application remains inconsistent in general clinical practice compared with specialist gastroenterology practice.

There is strong evidence of excessive diagnostic testing in Brazil, he said. “Studies show that even physicians who are familiar with the Rome Criteria tend to overuse diagnostic testing for DGBI. A survey of primary care providers found that they were more likely to order confirmatory tests and less likely to use a positive diagnostic strategy than specialists,” he said.

According to Waitzberg, this extensive testing is not only unnecessary and costly but also can be counterproductive because it may delay treatment and increase patient anxiety.

He identified several factors that may contribute to excessive testing, including diagnostic uncertainty, pressure from patients, fear of lawsuits related to missed diagnoses, medical training focused on laboratory and imaging tests, and clinical culture that continues to treat DGBI as a diagnosis of exclusion.

Waitzberg outlined several evidence-based strategies that could help improve this situation. In medical education, for example, he believes the Rome Criteria should be taught through practical application, not only through theoretical instruction, but also through clinical simulations and case discussions. “Teaching needs to connect the criteria to real world clinical reasoning, showing when tests are necessary and when they are not,” he emphasized.

He also noted that guidelines recommend a limited set of initial tests, including a complete blood count, C-reactive protein, and serologic testing for celiac disease in all patients, regardless of bowel habit. “In patients younger than 45 years with diarrhea, fecal calprotectin should be measured and, if positive, colonoscopy should be performed to exclude inflammatory bowel disease. Colonoscopy should be performed in patients with warning signs or those aged ≥ 50 years who have not previously undergone colorectal cancer screening,” Waitzberg said.

Another important consideration is the physician-patient relationship. Waitzberg emphasized the importance of training physicians to communicate diagnoses based on clinical criteria with confidence. Clear national guidelines on the initial diagnostic approach for DGBI are also needed. “Cultural change is slow, but it starts in medical school. Identifying the problem during medical training provides an important opportunity for intervention,” he emphasized.

Teresa Santos is a journalist and biologist with a bachelor’s degree in Genetics and a master’s degree in Biodiversity and Evolutionary Biology from the Federal University of Rio de Janeiro (UFRJ).

Ilana Polistchuck is a journalist and physician with a master’s degree in communication and Culture from the UFRJ. She is a specialist in Internal Medicine, having completed her residency at the Andaraí Federal Hospital in Rio de Janeiro, and in Family and Community Medicine, having completed her training through the Brazilian Society of Family and Community Medicine. 

This story was translated from Medscape’s Portuguese edition.