Don’t Skip this Article -Rome IV Summary

When I visited MIT, one of the slogans I heard was “Getting an Education from MIT is like taking a drink from a Fire Hose.” While this is a ridiculous notion, it is also true that the amount of information to consume, not just at MIT, but in so many areas is tremendous in quantity.  As such, one has to figure out what to read and what to toss.  For GI physicians, a recent summary (DA Drossman. Gastroenterol 2016; 1262-80) is worth a read due to the ubiquitous nature of the problems discussed.

Here were some key points:

  • “The possibility that passions or emotions could lead to the development of medical disease was first proposed by the Greek physician Claudius Galen.”
  • “Rome IV is a compendium of knowledge accumulated since Rome III” –10 years ago.

Some of the Changes:

  • New diagnoses:  Narcotic bowel syndrome, opioid-induced constipation, cannabinoid hyperemesis syndrome
  • Removal of functional terminology when possible…functional abdominal pain syndrome has been changed to centrally mediated abdominal pain syndrome
  • Threshold changes for diagnostic criteria
  • Addition of reflux hypersensitivity diagnosis.
  • Revision of Sphincter of Oddi  dysfunction disorder…  “driven by evidence that debunks the value of sphincterotomy for type III SOD.”
  • Emphasis that functional disorders exist on a spectrum with linked pathogenesis, particularly with regard to irritable bowel syndrome (IBS) subtypes.
  • Removal of the term discomfort for IBS criteria and using pain as the key criterion.

Approach to Patients with Functional GI Disorders:

  • The author discusses ways to engage patient to create partner-like interaction.
  • “Determine the immediate reason for the patient’s visit (eg. What led you to see me at this time?)”  Potential reasons: exacerbating factors, concern for serious disease, stressors, emotional comorbidity, impairment in daily functioning or hidden agenda (eg. disability, narcotics, litigation)
  • “Determine what the patient understands of the illness…What do you think is causing your symptoms?”
  • Provide a thorough explanation of the disorder.  “For example: ‘I understand you believe you have an infection that has been missed; as we understand it, the infection is gone but your nerves have even affected by the infection to make you feel like it is still there, similar to phantom limb.”
  • “Identify and respond realistically to the patient’s expectations for improvement (e.g. How do you feel I can be helpful to you?)”
  • Explain ways that stress can be associated.  “I understand you do not see stress as causing your pain, but you have mentioned how severe and disabling your  pain is.  How much do you think that is causing you emotional distress?”
  • “Set consistent limits..narcotic medication is not indicated because it can be harmful.”
  • “Involve patient in treatment plan (e.g. Let me suggest some treatments for you to consider).”
  • With regard to use of TCAs, the author explains that antidepressants can be used “to turn down the pain, and pain benefit occurs in doses lower than that used for depression.”  “Tricyclic antidepressants or the serotonin-norepinephrine reuptake inhibitors help control pain via central analgesia as well as provide relief of associated depressive symptoms.  The selective serotonin reuptake inhibitors are less effective for pain but can help reduce anxiety and associated depression.”
  • Establish an ongoing relationship.  “Whatever the result of this treatment, I am prepared to consider other options, and I will continue to work with you through this.”

My take: This summary provides a succinct update on a 6-year effort of 117 investigators/clinicians from 23 countries.  After reading this article, you will probably want to glance at the other articles in the same issue.

Vik Muniz Collage

Vik Muniz Collage

A closer look at the front wheel

A closer look at the front wheel

Clinically Useful Biomarkers for Irritable Bowel Syndrome?

A selected summary (Gastroenterol 2016; 150: 277-79) provides good insight into the subject of irritable bowel syndrome (IBS) biomarkers.  This summary focuses on a study by Pimental M et al (PLoS One 2015; 10: e0126438).

“In this study, the authors validated 2 serum biomarkers, antibodies (Abs) to cytolethal distending toxin (CdtB) and vinculin, primarily focused on differentiating diarrhea-predominant IBS (IBS-D) from IBD. CdtB is a bacterial toxin commonly produced by Campylobacter jejuni, as well as Escherichia coli, Salmonella, and Shigella…presence of Cdtb seems to be positively associated with the likelihood of developing a postinfectious IBS phenotype…Vinculin is a host cell adhesion protein, with which anti-CdtB Abs are known to cross-react.”

The study recruited 2681 participants (18-65 years) from 180 centers; most (n=2375) had Rome III IBS-D.

Key findings:

  • Anti-CdtB levels were higher in IBS-D 2.53 (± 0.69) compared with Crohn’s disease 1.72 (± 0.81), ulcerative colitis 1.54 (± 0.68), celiac disease 2.23 (± 0.70), and healthy subjects 1.81 (± 0.73)
  • Anti-vinculin Abs were higher in IBS-D as well: 1.34 (± 0.85) compared with Crohn’s disease 1.05 (± 0.91),ulcerative colitis 0.96 (± 0.77), celiac disease 1.07 (± 0.98), and healthy subjects 0.81 (± 0.59)

“Using a cutoff point of >2.80 for anti-CdtB Abs, the sensitivity was 43.7%, specificity was 91.6%.”  The positive likelihood ratio (LR) was 5.2 with this cutoff.  For vinculin, a cutoff of >1.68, resulted in a sensitivity of 32.6%, specificity of 83.8%, and a positive LR of 2.0.

For comparison, the commentary notes that the Rome III criteria in one study had a sensitivity of 68.8%, specificity of 79.5%, and positive LR of 3.35.

“The current study is important for 2 reasons.  First, that these 2 Abs were able to differentiate IBS-D from IBD and healthy controls, with a reasonable degree of accuracy, suggests that a substantial proportion of individuals with IBS may have an overt or subclinical postinfectious trigger, resulting in intestinal microbial disturbances…Second, the ability of these tests, if positive, to rule in IBS-D and rule out IBD is encouraging.”

But…

  • This study may not be representative of a typical primary care population with IBS
  • And,”as a rule of thumb, positive LRs of >10 are very useful in ruling in a disease…the complex, and likely multifactorial etiology of IBS may mean that a single biomarker that can diagnose IBS with the accuracy required for a test to be clinically useful is not possible.”

My take: I would like to see pediatric studies, perhaps this would help determine if a postinfectious mechanism is more common in children and adolescents.

Related blog posts:

Plantains

Plantains

Eluxadoline for Irritable Bowel Syndrome with Diarrhea

A recent study (AJ Lembo et al. NEJM 2016; 374: 242-53) found that eluxadoline, an oral agent with mixed opioid effects was helpful in some with irritable bowel syndrome with diarrhea (IBS-D).

Study methods: 2427 adults with IBS-D received either 75 mg, 100 mg of study medication or placebo twice daily for 26 weeks.  The primary endpoint was a composite response of decreased abdominal pain and stool consistency.

Eluxadoline in IBS

Eluxadoline in IBS.  Primary efficacy end point was defined as the proportion of patients who recorded a reduction of 30% or more from baseline in the daily average score for their worst abdominal pain for at least 50% of days assessed and, on the same days, a daily stool consistency score of less than 5.  Panel A: weeks 1-12.  Panel B for weeks 1-26.

While the absolute difference in response compared to placebo appears modest (see Figure above), the authors note that the treatment effects “were similar to those reported with alosetron and rifaximin.” Adverse effects included nausea (7.5% in 100 mg group compared with 5.1% in placebo), constipation (8.6%% in 100 mg group compared with 2.5% in placebo), and abdominal pain (7.2% in 100 mg group compared with 4.1% in placebo).  Pancreatitis developed in 5 patients in the treatment group (0.3%).

My take: While Eluxadoline helped some with IBS-D, better, more effective treatments are needed.

Related blog post:

Eating the Right Foods and Weight Loss

In a recent NY Times article, Rethinking Weight Loss and the Reasons We’re ‘Always Hungry’, the idea that too many calories causes obesity is challenged:

“…overeating doesn’t make you fat. The process of getting fat makes you overeat.”

Here’s an excerpt:

Dr. Ludwig, an obesity expert and professor of nutrition at the Harvard T.H. Chan School of Public Health, argues that weight gain begins when people eat the wrong types of food, which throws their hormones out of whack and sets off a cycle of cravings, hunger and bingeing. In his new book, “Always Hungry?,” he argues that the primary driver of obesity today is not an excess of calories per se, but an excess of high glycemic foods like sugar, refined grains and other processed carbohydrates…

Simply cutting back on calories as we’ve been told actually makes the situation worse. When we cut back on calories, our body responds by increasing hunger and slowing metabolism. It responds in an effort to save calories…

It’s the low fat, very high carbohydrate diet that we’ve been eating for the last 40 years, which raises levels of the hormone insulin and programs fat cells to go into calorie storage overdrive.

My take: The idea of changing the types of foods that we consume is not new in the fight against excessive weight gain.  Some of the best data on healthy eating is associated with the Mediterranean diet.

Related blog posts:

Another review (from the NY Times) of the book ‘Happy Gut’ describes a diet promoted by a NY internist to help with problems like irritable bowel: Seeking a ‘Happy Gut’ for Better Health. “Cutting out dairy and gluten reversed many of his symptoms. Replacing processed foods with organic meats, fresh vegetables and fermented foods gave him more energy and settled his sensitive stomach.”

Banning Mills

Banning Mills

 

Should Patients with IBS be Screened for Celiac Disease?

Despite widespread expert opinion that those with irritable bowel syndrome (IBS) should be screened for celiac disease, whether it is a good idea is not settled.  A recent study (RS Choung et al. Clin Gastroenterol Hepatol 2015; 13: 1937-43) showed that celiac disease has a low prevalence in US patients (mean age 61 yrs in this cohort) with IBS.

Here’s an excerpt of a summary of this report from the AGA Blog: “Should all Patients with IBS be Screened for Celiac Disease?”

Rok Seon Choung et al investigated whether subjects with positive results from serologic tests for celiac disease are frequently diagnosed with IBS or other functional gastrointestinal disorders (FGIDs).

They sent self-report bowel disease questionnaires to 7217 residents of Olmsted County, Minnesota, to collect data on symptoms compatible with functional GI disorders, including IBS, collecting data on symptoms compatible with functional GI disorders, including IBS. These symptom data were linked to surveys of undiagnosed celiac disease conducted among more than 47,000 individuals from the same region, based on results of tests for immunoglobulin A tissue transglutaminase and then endomysial antibody.

Among the 3202 subjects who completed the questionnaires and had their serum sample analyzed, 13.6% had IBS and 55.2% had some gastrointestinal symptoms.

The prevalence of celiac disease, based on serologic markers, was 1.0%. However, whereas 3% of patients with celiac disease met the criteria for IBS, 14% of patients without celiac disease met the criteria for IBS.

Abdominal pain, constipation, weight loss, and dyspepsia were the most frequent symptoms reported by subjects who tested positive for celiac disease, but none of the gastrointestinal symptoms or disorders were significantly associated with results of serologic test for celiac disease.

My take: This study along with others show that celiac disease is infrequent in patients with IBS.  Since the symptoms of celiac disease overlap with IBS, I doubt this study will dissuade practitioners from screening for celiac despite the low yield.

Also, this fall I posted several blogs on GMOs.  An interesting article (from Vox/Grist) on this subject explains how GMOs are a lot like pornography: It’s practically impossible to define “GMOs”

Leaving Work

Atlanta Sky

The Science Behind IBS Dietary Interventions

A succinct review (BE Lacy. Clin Gastroenterol Hepatol 2015; 13: 1899-1906) reviews the topic of dietary interventions for irritable bowel syndrome (IBS).

Here are some of the points:

  • “True food allergies are present in 1% to 4% of the US population, but are not more prevalent in IBS patients.”
  • One study found that “more than 1 in 4 patients with self-reported NCGS [nonceliac gluten sensitivity] actually fulfill the diagnosis.”  In other words, most patients with self-reported NCGS do not have NCGS.
  • “The prevalence of lactase deficiency is similar, or slightly higher, in IBS patients compared with healthy subjects; however, the self-reporting of symptoms attributed to lactose intolerance is not reliable.”
  • Potential mechanisms of food triggering GI symptoms were discussed, including intestinal permeability, visceral hypersensitivity, small intestine bacterial overgrowth, and gut microbiome.

Another article which covers the same topic: PR Gibson et al. Gastroenterol 2015; 148: 1158-74.

 

Which Diet is Best for Irritable Bowel Syndrome?

As noted in this blog previously, there has been increasing evidence that a low FODMAPs (fermentable oligo-, di-, monosaccharides and polyols) diet is an effective option for irritable bowel syndrome (IBS) in adults and children. Now, a study (L Bohn et al. Gastroenterol 2015; 149: 1399-1407) directly compares a low FODMAPs diet with an IBS diet in a multicenter, parallel, single-blind study of 75 patients (adults) with Rome III criteria for IBS.

The comparison IBS diet recommended regular meal patterns, avoidance of large meals, reduced intake of fat and reduced insoluble fibers, caffeine, and gas-producing foods, such as beans, cabbage and onions.  In addition, this diet recommended avoidance of spicy foods, coffee, alcohol, soft drinks, and sweeteners that end with “-ol.” This diet has been recommended by the British Dietetic Association and by the National Institute for Health and Care Excellence (NICE).  NICE Guidelines for IBS

Key findings:

  • 67 patients completed the study.  The severity of IBS symptoms improved in both groups (P<.0001) without a difference between the two groups
  • 19 (50%) of low FODMAPs had reductions in IBS severity scores of >50 compared with baseline and 17 patients (46%) in the ‘traditional’ IBS diet group had this degree of improvement.

My take: Diet changes often result in symptom improvement in IBS.  Both of these diets can be recommended in patients with IBS.

Atlanta Sky

Atlanta Sky

FODMAPS Advice From Harvard

A recent post from Harvard Health Publications offers a succinct explanation of a low FODMAPs diet for irritable bowel syndrome.

Here’s the link: Try a FODMAPs diet to manage irritable bowel syndrome

 

Related blog posts:

Low FODMAPs Diet in Pediatric Irritable Bowel

A low FODMAPs diet has been associated with clinical improvement in adults with irritable bowel syndrome and “gluten sensitivity” (see links below).  Now, there is more data that this diet can be effective in the pediatric population (Chumpitazi BP, et al. Aliment Pharm Ther DOI: 10.1111/apt.13286. Article first published online: 24 JUN 2015 -Thanks to KT Park for this reference).  In addition, this small study (n=33) tries to correlate changes in symptoms with changes in the gut microbiome. Interestingly, the dietary trials were only 48 hours.

From the methods: Following a 7-day baseline period, “we employed a randomised, double-blind, crossover study design. Subjects received either a low FODMAP or typical American childhood diet (TACD) for 48 h. After 48 h on the first assigned diet, they returned to their habitual diet for 5 days. Following this 5-day washout period, they were crossed over to the other intervention diet for 48 h.”

Here is the abstract and a link to the full text: Randomised clinical trial: gut microbiome biomarkers are associated with clinical response to a low FODMAP diet in children with the irritable bowel syndrome

Abstract:

Background

A low fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAP) diet can ameliorate symptoms in adult irritable bowel syndrome (IBS) within 48 h.

Aim

To determine the efficacy of a low FODMAP diet in childhood IBS and whether gut microbial composition and/or metabolic capacity are associated with its efficacy.

Methods

In a double-blind, crossover trial, children with Rome III IBS completed a 1-week baseline period. They then were randomised to a low FODMAP diet or typical American childhood diet (TACD), followed by a 5-day washout period before crossing over to the other diet. GI symptoms were assessed with abdominal pain frequency being the primary outcome. Baseline gut microbial composition (16S rRNA sequencing) and metabolic capacity (PICRUSt) were determined. Metagenomic biomarker discovery (LEfSe) compared Responders (≥50% decrease in abdominal pain frequency on low FODMAP diet only) vs. Nonresponders (no improvement during either intervention).

Results

Thirty-three children completed the study. Less abdominal pain occurred during the low FODMAP diet vs. TACD [1.1 ± 0.2 (SEM) episodes/day vs. 1.7 ± 0.4, P < 0.05]. Compared to baseline (1.4 ± 0.2), children had fewer daily abdominal pain episodes during the low FODMAP diet (P < 0.01) but more episodes during the TACD (P < 0.01). Responders were enriched at baseline in taxa with known greater saccharolytic metabolic capacity (e.g. Bacteroides, Ruminococcaceae, Faecalibacterium prausnitzii) and three Kyoto Encyclopedia of Genes and Genomes orthologues, of which two relate to carbohydrate metabolism.

Conclusions

In childhood IBS, a low FODMAP diet decreases abdominal pain frequency. Gut microbiome biomarkers may be associated with low FODMAP diet efficacy.

Related blog posts:

Baseball Broadcast with a Sense of Humor

Baseball Broadcast with a Sense of Humor

FDA Approves Rifaximin and Eluxadoline for IBS-D

From FDA (5/27/15): Two New FDA-Approved Treatments for adults with IBS-D

Excerpt:

The U.S. Food and Drug Administration today approved Viberzi (eluxadoline) and Xifaxan (rifaximin), two new treatments, manufactured by two different companies, for irritable bowel syndrome with diarrhea (IBS-D) in adult men and women….

“For some people, IBS can be quite disabling, and no one medication works for all patients suffering from this gastrointestinal disorder,” said Julie Beitz, M.D., director of the Office of Drug Evaluation III in FDA’s Center for Drug Evaluation and Research. “The approval of two new therapies underscores the FDA’s commitment to providing additional treatment options for IBS patients and their doctors.”

Viberzi, which contains a new active ingredient, is taken orally twice daily with food. Viberzi activates receptors in the nervous system that can lessen bowel contractions. Viberzi is intended to treat adults with IBS-D.

Xifaxan can be taken orally three times a day for 14 days, for the treatment of abdominal pain and diarrhea in patients with IBS-D. Patients who experience a recurrence of symptoms can be retreated with a 14 day treatment course, up to two times. Xifaxan, an antibiotic derived from rifampin, was previously approved as treatment for travelers’ diarrhea caused by E. coli and for reduction of the risk in adult patients of recurring overt hepatic encephalopathy, the changes in brain function that occur when the liver is unable to remove toxins from the blood. The exact mechanism of action of Xifaxan for treatment of IBS-D is not known, but is thought to be related to changes in the bacterial content in the gastrointestinal tract.

The safety and effectiveness of Viberzi for treatment of IBS-D were established in two double-blind, placebo-controlled clinical trials…Results showed Viberzi was more effective in simultaneously reducing abdominal pain and improving stool consistency than placebo over 26 weeks of treatment.

The safety and effectiveness of Xifaxan for treatment of IBS-D were established in three double-blind, placebo-controlled trials.

Related blog posts: