Tag Archives: Gastroenterology

Unexplained Digestive Problems? Lone Star Tick Bites May Be To Blame

The American Gastroenterological Association (AGA) has released new clinical guidance to help physicians and patients identify if unexplained digestive symptoms are due to alpha-gal syndrome, a food allergy that is caused by lone star tick bites. The AGA Clinical Practice Update was published today (March 21, 2023) in the medical journal Gastroenterology.

Alpha-gal syndrome is an allergy that causes your body to react to eating meat from mammals and products made from mammals. Symptoms usually start 2-6 hours after eating the mammalian meat or food.

Clinicians should consider alpha-gal syndrome in patients with unexplained gastrointestinal symptoms of abdominal pain, diarrhea, nausea, and vomiting, particularly those who live or have lived in an alpha-gal–prevalent area (this includes the Southeast, mid-Atlantic, Midwest, and East Central U.S. regions). For patients with suspected alpha-gal, there is a blood test that looks for immunoglobulin E antibodies (IgE) to alpha-gal. Patients with these antibodies may have alpha-gal allergy. The main treatment for alpha-gal allergy is to not eat foods that contain alpha-gal. This includes mammalian meat, fat, and products made from them.

About Alpha-gal syndrome

Alpha-gal syndrome is an allergy that causes your body to respond badly to ingesting mammalian products; meat from mammals or products made from mammals such as cheese, butter, milk, cream, gelatin, etc. Mammals are animals that have hair, such as cows, pigs, and deer.  Symptoms usually start 2-6 hours after eating the mammalian meat or food. The alpha-gal allergy can cause symptoms of the gastrointestinal tract (digestive system) like stomach pain, diarrhea (loose stool), nausea or upset belly, and vomiting (throwing up). It can also cause hives (an itchy rash), flushing of the skin, swelling of the face, or fainting.

About lone star ticks

Lone star ticks (Amblyomma americanum) are a species of tick found predominantly in the southeastern and eastern United States. They are named for the distinctive white spot on the back of adult females, which resembles the shape of the state of Texas. Lone star ticks are known for their aggressive behavior, feeding on a variety of hosts, including humans, dogs, and deer. They are also known to carry diseases such as Rocky Mountain spotted fever, tularemia, and alpha-gal syndrome, a food allergy that causes the body to react to mammalian meat.

As the official journal of the AGA Institute, Gastroenterology is the leading publication in the field of gastrointestinal disease. It provides reliable and current coverage of both clinical and basic gastroenterology, with regular contributions from renowned experts and the latest information on disease treatments. Original research is categorized by clinical and basic-translational content, as well as by content related to the alimentary tract, liver, pancreas, and biliary system.

New MIT/Caltech Ingestible Sensor Could Help Doctors Pinpoint GI Difficulties

The sensor sends out its location as it moves through the GI tract, revealing where slowdowns in digestion may occur.

Engineers at MIT and Caltech have demonstrated an ingestible sensor whose location can be monitored as it moves through the digestive tract, an advance that could help doctors more easily diagnose gastrointestinal motility disorders such as constipation, gastroesophageal reflux disease, and gastroparesis.

The tiny sensor works by detecting a magnetic field produced by an electromagnetic coil located outside the body. The strength of the field varies with distance from the coil, so the sensor’s position can be calculated based on its measurement of the magnetic field.

In the new study, the researchers showed that they could use this technology to track the sensor as it moved through the digestive tract of large animals. Such a device could offer an alternative to more invasive procedures, such as endoscopy, that are currently used to diagnose motility disorders.

“Many people around the world suffer from GI dysmotility or poor motility, and having the ability to monitor GI motility without having to go into a hospital is important to really understand what is happening to a patient,” says Giovanni Traverso, an associate professor of mechanical engineering at MIT and a gastroenterologist at Brigham and Women’s Hospital.

Traverso is one of the senior authors of the new study, along with Azita Emami, a professor of electrical engineering and medical engineering at Caltech, and Mikhail Shapiro, a professor of chemical engineering at Caltech and an investigator of the Howard Hughes Medical Institute. Saransh Sharma, a graduate student at Caltech, and Khalil Ramadi SM ’16, PhD ’19, a graduate of the Department of Mechanical Engineering and the Harvard-MIT Program in Health Sciences and Technology who is now an assistant professor of bioengineering at New York University, are the lead authors of the paper, which was recently published in the journal Nature Electronics.

GI motility disorders, which affect about 35 million Americans, can occur in any part of the digestive tract, resulting in failure of food to move through the tract. They are usually diagnosed using nuclear imaging studies or X-rays, or by inserting catheters containing pressure transducers that sense contractions of the GI tract.

The MIT and Caltech researchers wanted to come up with an alternative that would be less invasive and could be done at the patient’s home. Their idea was to develop a capsule that could be swallowed and then send out a signal revealing where it was in the GI tract, allowing doctors to determine what part of the tract was causing a slowdown and better determine how to treat the patient’s condition.

To achieve that, the researchers took advantage of the fact that the field produced by an electromagnetic coil becomes weaker, in a predictable way, as the distance from the coil increases. The magnetic sensor they developed, which is small enough to fit in an ingestible capsule, measures the surrounding magnetic field and uses that information to calculate its distance from a coil located outside the body.

“Because the magnetic field gradient uniquely encodes the spatial positions, these small devices can be designed in a way that they can sense the magnetic field at their respective locations,” Sharma says. “After the device measures the field, we can back-calculate what the location of the device is.”

To accurately pinpoint a device’s location inside the body, the system also includes a second sensor that remains outside the body and acts as a reference point. This sensor could be taped to the skin, and by comparing the position of this sensor to the position of the sensor inside the body, the researchers can accurately calculate where the ingestible sensor is in the GI tract.

The ingestible sensor also includes a wireless transmitter that sends the magnetic field measurement to a nearby computer or smartphone. The current version of the system is designed to take a measurement any time it receives a wireless trigger from a smartphone, but it can also be programmed to take measurements at specific intervals.

“Our system can support localization of multiple devices at the same time without compromising the accuracy. It also has a large field of view, which is crucial for human and large animal studies,” Emami says.

The current version of the sensor can detect a magnetic field from electromagnetic coils within a distance of 60 centimeters or less. The researchers envision that the coils could be placed in the patient’s backpack or jacket, or even the back of a toilet, allowing the ingestible sensor to take measurements whenever it is in range of the coils.

The researchers tested their new system in a large animal model, placing the ingestible capsule in the stomach and then monitoring its location as it moved through the digestive tract over several days.

In their first experiment, the researchers delivered two magnetic sensors attached to each other by a small rod, so they knew the exact distance between them. Then, they compared their magnetic field measurements to this known distance and found that the measurements were accurate to a resolution of about 2 millimeters — much higher than the resolution of previously developed magnetic-field-based sensors.

Next, the researchers performed tests using a single ingestible sensor along with an external sensor attached to the skin. By measuring the distance from each sensor to the coils, the researchers showed that they could track the ingested sensor as it moved from the stomach to the colon and then was excreted. The researchers compared the accuracy of their strategy with measurements taken by X-ray and found that they were accurate within 5 to 10 millimeters.

“Using an external reference sensor helps to account for the problem that every time an animal or a human is beside the coils, there is a likelihood that they will not be in exactly the same position as they were the previous time. In the absence of having X-rays as your ground truth, it’s difficult to map out exactly where this pill is, unless you have a consistent reference that is always in the same location,” Ramadi says.

This kind of monitoring could make it much easier for doctors to figure out what section of the GI tract is causing a slowdown in digestion, the researchers say. “The ability to characterize motility without the need for radiation, or more invasive placement of devices, I think will lower the barrier for people to be evaluated,” Traverso says.

The researchers now hope to work with collaborators to develop manufacturing processes for the system and further characterize its performance in animals, in hopes of eventually testing it in human clinical trials.

For more on this device, see “Smart Pills” Transform Diagnosis and Treatment of Gastrointestinal Disorders.

Reference: “Location-aware ingestible microdevices for wireless monitoring of gastrointestinal dynamics” by Saransh Sharma, Khalil B. Ramadi, Nikhil H. Poole, Shriya S. Srinivasan, Keiko Ishida, Johannes Kuosmanen, Josh Jenkins, Fatemeh Aghlmand, Margaret B. Swift, Mikhail G. Shapiro, Giovanni Traverso and Azita Emami, 13 February 2023, Nature Electronics.
DOI: 10.1038/s41928-023-00916-0

The research was funded by the National Science Foundation, the Rothenberg Innovation Initiative, and the Heritage Medical Research Institute.

Long COVID Means Increased Risk of Long-Term Gastrointestinal Problems

People who have had COVID-19 are at increased risk of developing gastrointestinal (GI) disorders within a year after infection compared with people who haven’t been infected. This is according to an analysis of federal health data by researchers at Washington University School of Medicine in St. Louis and the Veterans Affairs St. Louis Health Care system.

Such conditions include liver problems, acute pancreatitis, irritable bowel syndrome, acid reflux, and ulcers in the lining of the stomach or upper intestine. The post-COVID-19 GI tract also is associated with an increased likelihood of constipation, diarrhea, abdominal pain, bloating, and vomiting.

“Gastrointestinal problems were among the first that were reported by the patient community,” said senior author Ziyad Al-Aly, MD, a clinical epidemiologist at Washington University who has studied extensively the long-term effects of COVID-19 infection. “It is increasingly clear that the GI tract serves as a reservoir for the virus.”

The study was published on March 7 in the journal Nature Communications.

The new findings build upon Al-Aly’s prior research detailing COVID-19’s lingering effects on the brain, heart, kidneys and other organs. Since the pandemic, Al-Aly and his research team have published numerous, often-cited studies on SARS-CoV-2’s extended health risks, altogether noting about 80 adverse health outcomes associated with long COVID-19.

“At this point in our research, the findings on the GI tract and long COVID did not surprise us,” Al-Aly said. “The virus can be destructive, even among those considered healthy or who have had mild infections. We’re seeing COVID-19’s ability to attack any organ system in the body, sometimes with serious long-term consequences, including death.”

The gastrointestinal system includes the mouth, throat, esophagus, stomach, small and large intestines, rectum, and anus, as well as organs, such as the liver and pancreas, that produce enzymes to aid in the digestion of food and liquids.

GI conditions range from mild stomach issues to life-threatening conditions such as liver failure and acute pancreatitis.

The researchers estimate that, so far, infections caused by SARS-CoV-2 have contributed to more than 6 million new cases of GI disorders in the U.S. and 42 million new cases worldwide.

“This is no small number,” said Al-Aly, who treats patients within the VA St. Louis Health Care System and is its chief of research and development service. “It is crucial to include GI health as an integral part of post-acute COVID care.”

For the study, researchers analyzed about 14 million de-identified medical records in a database maintained by the U.S. Department of Veterans Affairs, the nation’s largest integrated healthcare system.

They created a controlled data set of 154,068 people who had tested positive for COVID-19 sometime from March 1, 2020, through January 15, 2021, and who had survived the first 30 days after infection. Statistical modeling was used to compare gastrointestinal outcomes in the COVID-19 data set with two other groups of people not infected with the virus: a control group of more than 5.6 million people who did not have COVID-19 during the same time frame; and a control group of more than 5.8 million people from March 1, 2018, to December 31, 2019, well before the virus had infected and killed millions across the globe.

Overall, GI disorders were 36% more likely in people with COVID-19 compared with those who had not been infected with the virus. This includes people who were and were not hospitalized because of the virus.

“A lot of people draw comparisons between COVID-19 and the flu,” Al-Aly said. “We compared health outcomes in those hospitalized with the flu versus those hospitalized with COVID, and we still saw an increased risk of GI disorders among people hospitalized with COVID-19. Even this far into the pandemic, COVID-19 remains more serious than the flu.”

People in the study were mostly older white men; however, the researchers also analyzed data that included more than 1.1 million women and adults of all ages and races. “Those who acquired long-term GI problems after infection included people of all ages, sexes, and racial backgrounds,” Al-Aly said.

Additionally, few people in the study had been vaccinated for COVID-19 because the vaccines were not yet widely available during the time span of the study, from March 2020 through early January 2021. The data also predates the delta, omicron, and other COVID-19 variants, and newer data indicate the COVID-19 vaccines provide at least some protection against long COVID-19.

“While the vaccines may help to reduce the risks of long COVID, they do not offer complete protection against long-term symptoms of COVID-19 that can affect the heart, lungs, brain, and now, we know, the GI tract,” Al-Aly said.

Compared with patients in the control groups, people who had had COVID-19 were at a 62% increased risk of developing ulcers in the lining of the stomach or small intestine; a 35% heightened risk of suffering from acid reflux disease; and a 46% increased risk of experiencing acute pancreatitis.

Also compared to control groups, patients who had had the virus were 54% more likely to suffer from irritable bowel syndrome, 47% more likely to experience inflammation of the stomach lining, and 36% more likely to have an upset stomach without an obvious cause.

Similarly, those who had had COVID-19 were 54% more likely to experience digestive symptoms such as constipation, diarrhea, bloating, vomiting, and abdominal pain.

“Taken with all the evidence that has accumulated thus far, the findings in this report call for the urgent need to double down and accelerate our effort to develop strategies to prevent and treat the long-term health effects after COVID-19 infection,” Al-Aly said.

Reference: “Long-term gastrointestinal outcomes of COVID-19” by Evan Xu, Yan Xie and Ziyad Al-Aly, 7 March 2023, Nature Communications.
DOI: 10.1038/s41467-023-36223-7

New Research Links Irritable Bowel Syndrome to Reduced Bacterial Diversity

According to a team of Korean researchers, individuals with Irritable Bowel Syndrome (IBS) have a decreased diversity of bacteria in their intestines compared to healthy individuals. This is the first study to establish a clear connection between IBS and a reduction in gut microbiota diversity. The findings were published in the American Society for Microbiology’s journal Microbiology Spectrum.

Normally, “More than 10,000 species of microorganism live in the human intestine,” said corresponding author Jung Ok Shim, M.D., Ph.D., professor of Pediatric Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Korea University College of Medicine, Seoul. Disruption of the microbiome of the human gastrointestinal tract can trigger IBS. Typically, IBS causes bloating, diarrhea, and stomach pain or cramps.

Previous studies of gut bacteria in patients with IBS have been controversial, with inconsistent results, due to small sample size and lack of consistent analytical methods used among these studies, said Shim. The investigators combined their own dataset with 9 published, shared datasets, encompassing 576 IBS patients and 487 healthy controls, analyzing them with a “unified data processing and analytical method.”

The researchers found that the gut bacterial community is less diverse in IBS patients than in healthy people, said Shim. Additionally, the abundance of 21 bacterial species differed between IBS patients and healthy controls. However, the findings were not statistically significant in the pediatric cohort due to a small sample size.

The investigators proved that the disturbed gut bacterial community “is associated with IBS, though this does not mean that the relationship is causal,” said Shim. “Functional studies are needed to prove whether the change in gut micro-organisms contributes to the development of IBS.”

Even though IBS is a common disorder, its pathogenesis remains unknown, and as yet there is no effective treatment strategy. “Based on the epidemiological studies of IBS patients, altered gut microbiota was proposed as one of the possible causes of IBS,” the researchers write. “Acute bacterial gastroenteritis can cause chronic, asymptomatic, low-grade intestinal wall inflammation sufficient to alter neuromuscular and epithelial cell function.”

“Gut Bacterial Dysbiosis in Irritable Bowel Syndrome: a Case-Control Study and a Cross-Cohort Analysis Using Publicly Available Data Sets” by Gun-Ha Kim, Kihyun Lee and Jung Ok Shim, 18 January 2023, Microbiology Spectrum.
DOI: 10.1128/spectrum.02125-22

New Clinical Trial Reveals: Cutting Just One Food Can Treat Eosinophilic Esophagitis

A clinical trial funded by the National Institutes of Health has found that eliminating just animal milk from the diet of adults with eosinophilic esophagitis (EoE) is as effective in treating the condition as eliminating animal milk and five other common foods. The researchers noted that for individuals with EoE whose disease persists even after avoiding animal milk, a stricter diet may assist them in achieving remission. These results were recently published in the journal The Lancet Gastroenterology & Hepatology.

“Diet-based therapy for eosinophilic esophagitis will be much easier to follow for many people if it involves cutting just one food from the diet rather than six,” said Hugh Auchincloss, M.D., acting director of the National Institute of Allergy and Infectious Diseases (NIAID), part of NIH.

EoE is a chronic disease characterized by an overabundance of white blood cells called eosinophils in the esophagus. Allergic inflammation due to food drives the disease by damaging the esophagus and preventing it from working properly. For people with EoE, swallowing even small amounts of food can be a painful and stressful choking experience. About 160,000 people in the United States are living with EoE.

Excluding certain foods from the diet has been a cornerstone of EoE treatment. During the early 2000s, researchers found that eliminating six common food triggers of esophageal injury—milk, egg, wheat, soy, fish, and nuts—substantially reduced signs and symptoms of EoE. This six-food elimination diet (6FED) became a common approach to managing the disease.

In recent years, scientists have conducted small, non-randomized studies of removing one to four of the most common food antigens from the diet to treat EoE, with some success. However, the relative risks and benefits of eliminating many foods versus a few foods at the start of diet-based therapy remained unclear.

The new findings come from the first multi-site, randomized trial comparing the 6FED with a one-food elimination diet (1FED) in adults with EoE. The trial was co-funded by NIAID, the National Center for Advancing Translational Sciences, and the National Institute of Diabetes and Digestive and Kidney Diseases, all part of NIH. Marc E. Rothenberg, M.D., Ph.D., the senior author of the published study, is director of both the Division of Allergy and Immunology and the Cincinnati Center for Eosinophilic Disorders at Cincinnati Children’s.

The trial involved 129 adults ages 18 to 60 years with a confirmed EoE diagnosis, active EoE symptoms, and a high number of eosinophils in esophageal tissue. Volunteers enrolled in the trial at one of 10 U.S. medical centers that participate in the Consortium of Eosinophilic Gastrointestinal Disease Researchers, part of the NIH-funded Rare Diseases Clinical Research Network. Participants were assigned at random to either the 1FED, which eliminated only animal milk from the diet, or the 6FED.

They followed their assigned diet for six weeks, then underwent an upper endoscopy exam and an esophageal tissue biopsy. If the number of eosinophils in the tissue indicated that EoE was in remission, the participant exited the study. If EoE was not in remission, people who had been on 1FED could advance to 6FED, and people who had been on 6FED could take topical swallowed steroids, both for six weeks, followed by a repeat exam with tissue biopsy.

The investigators found that 34% of participants on 6FED and 40% of participants on 1FED achieved remission after six weeks of diet therapy, a difference that was not statistically significant. The two diets also had a similar impact across several other measures, including a reduction in EoE symptoms and an effect on quality of life. Thus, 1FED and 6FED were equally effective at treating EoE, an unexpected finding.

The researchers also discovered that nearly half of the people who did not respond to 1FED attained remission after treatment with the more restrictive 6FED, while more than 80% of the non-responders to 6FED achieved remission with oral steroids.

Taken together, the investigators conclude that 1FED is a reasonable first-line diet therapy option in adults with EoE, and that effective therapies are available for people who do not achieve remission after 1FED or 6FED.

Reference: “One-food versus six-food elimination diet therapy for the treatment of eosinophilic oesophagitis: a multicentre, randomised, open-label trial” by Kara L Kliewer, Nirmala Gonsalves, Evan S Dellon, David A Katzka, Juan P Abonia, Seema S Aceves, Nicoleta C Arva, John A Besse, Peter A Bonis, Julie M Caldwell, Kelley E Capocelli, Mirna Chehade, Antonella Cianferoni, Margaret H Collins, Gary W Falk, Sandeep K Gupta, Ikuo Hirano, Jeffrey P Krischer, John Leung, Lisa J Martin and Marc E Rothenberg, 28 February 2023, The Lancet Gastroenterology & Hepatology.
DOI: 10.1016/S2468-1253(23)00012-2

The study was funded by the National Institute of Allergy and Infectious Diseases.

Necrotizing Enterocolitis – The Horrifying Intestinal Disease Too Many Babies Are Still Dying From

New research has found that in the US between 1999 and 2020, Black infants disproportionately died from necrotizing enterocolitis compared to White infants, despite overall improvements in the rates of death from the disease. This is according to a study published today (March 3, 2023) in JAMA Network Open 

Necrotizing enterocolitis (NEC) is one of the most common causes of death in preterm infants. Medically-fragile term infants, such as neonates born with a congenital heart defect, are also at an elevated risk of NEC. Two prior studies reported conflicting trends in NEC rates. One study from 2000-2011 showed increasing rates of death from the condition over time. Another study reported declining rates of NEC from 2006-2017.

Researchers in the current study wanted to determine the trends in NEC-related deaths in the US spanning both of these periods. They also examined racial disparities and geographic differences.

The study used data on US infant deaths from 1999 through 2020 from the Centers for Disease Control and Prevention and the National Center for Health Statistics. The researchers analyzed all infant deaths up to 1 year of age, with the underlying cause being NEC.

Of 88,125,233 live births, 8,951 infants died of NEC. Rates of NEC-related deaths per 100,000 live births were higher among Black infants (16.1) compared to White infants (6.4). The study found that in 2007, there was an inflection with a change in US trends in NEC-related deaths; NEC-related deaths decreased by 7.7% per year from 2007 through 2012. However, there were no additional declines after 2012. Racial differences in NEC-related deaths decreased over time, although in 2020, Black infants were still 2.5 times more likely to die from NEC than White infants.

Dr. Mattie Wolf, first-author of this study and a post-doctoral fellow at Emory University and Children’s Healthcare of Atlanta, notes, “These data clearly show improvements in NEC-related death in the US, although we do not know exactly what factors are driving these improvements.”

“Our results show we have made progress in reducing deaths related to NEC, but given the lack of improvements since 2012, we still have continued work to do to reduce the burden of this disease,” says Ravi Patel, MD, MSc, Associate Professor of Pediatrics at Emory University School of Medicine and Children’s Healthcare of Atlanta and senior author of this article.

Jennifer Canvasser, MSW, Founder and Executive Director of the NEC Society and co-author of the study, shares, “These data reveal that someone’s child died from NEC each day, on average, over this period. My son Micah is one of the 8,951 babies. Clinicians, scientists, and patient-families intimately understand the devastation of NEC. Together, with policy-makers and stakeholders who care, we are working tirelessly to improve outcomes and provide equitable care so that all babies can thrive and avoid the devastation of this disease.”

Reference: “Trends and Racial and Geographic Differences in Infant Mortality in the United States Due to Necrotizing Enterocolitis, 1999 to 2020” 3 March 2023, JAMA Network Open.
DOI: 10.1001/jamanetworkopen.2023.1511

Additional authors of this study include Allison Rose, MD, Ruchika Goel, MD, MPH, and Barbara J. Stoll, MD. The study was supported by the National Institutes of Health.

The NEC Society is a 501(c)(3) nonprofit organization dedicated to building a world without necrotizing enterocolitis (NEC) through research, advocacy, and education. The NEC Society is a patient-led organization that collaborates with expert clinicians and researchers to better understand, prevent, and treat this devastating neonatal intestinal disease.

Increased adenoma detection rate may significantly reduce post-colonoscopy colorectal cancer risk

A cohort study from the Italian Colorectal Cancer screening program including more than 49,000 colonoscopies found a significant inverse association between endoscopists’ proficiency as measured by adenoma detection rate (ADR) and post-colonoscopy colorectal cancer (PCCRC). These finding suggest that targeting only poor performing endoscopists with measures to increase ADR may significantly reduce PCCRC risk. The findings are published in Annals of Internal Medicine.

Colorectal cancer (CRC) population screening programs based on fecal testing (FITs) represent the standard of care for CRC prevention in many Western countries. The ultimate effectiveness of these screening procedures relies on the accurate detection and removal of precancerous lesions and early invasive cancer in colonoscopies of persons with positive FIT results. However, it is known that there are high miss rates and high rates of performance variability among endoscopists.

Researchers from Veneto Tumor Registry, Azienda Zero, Padova, “Sapienza” University of Rome and Humanitas University in Milan, Italy, conducted a population-based of 49,626 colonoscopies done by 113 endoscopists between 2012 and 2017 after a positive FIT result.

They report that 277 cases of PCCRC were diagnosed with a mean ADR of 48.3%. They noted a 2.35-fold cancer risk increase in the lowest performing endoscopists group compared to the highest performing group. According to the authors, endoscopist competence is key to screening effectiveness.

These results strongly suggest tailored targeting of low performing endoscopists with interventions aimed at helping them increase their ADR and consequently help their patients by reducing their PCCRC risk.

More information:
Manuel Zorzi et al, Adenoma Detection Rate and Colorectal Cancer Risk in Fecal Immunochemical Test Screening Programs, Annals of Internal Medicine (2023). DOI: 10.7326/M22-1008

Journal information:
Annals of Internal Medicine

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Cold snare polypectomy significantly reduces bleeding risk compared to hot snare polypectomy

A randomized controlled trial (RCT) of more than 4,000 people found that the risk for delayed bleeding after polypectomy was significantly reduced among persons who received a cold snare polypectomy. The findings are published in Annals of Internal Medicine.

More than 16 million colonoscopies are performed annually in the U.S., and polypectomy during colonoscopy plays a pivotal role in preventing . Hot snare polypectomy (HSP) has been conventionally used to remove polyps but is associated with a higher risk of delayed bleeding, post-polypectomy syndrome, or perforation. Previous research on cold snare polypectomy (CSP) demonstrated that CSP was as effective as HSP but more efficient in removing small polyps, but its effect on reducing delayed bleeding has been shown only in high-risk patients.

Researchers from National Taiwan University Hospital conducted an RCT of 4,270 participants who were undergoing polypectomy in six centers in Taiwan. They report that only 8 out of 2,137 persons, or 0.4%, experienced delayed bleeding after CSP. In comparison, 31 out of 2,133 persons, or 1.5%, experienced delayed bleeding after HSP. They also report that only 0.2% of CSP group had emergency service visits compared with 0.6% of the HSP group. The authors show that CSP was also more efficient, with the study’s results showing that the time required for polypectomy is reduced by 26.9%.

According to the authors, the findings support the superior safety of CSP over HSP in managing colorectal sized 10 mm or smaller in the .

More information:
Li-Chun Chang et al, Cold Versus Hot Snare Polypectomy for Small Colorectal Polyps, Annals of Internal Medicine (2023). DOI: 10.7326/M22-2189

Journal information:
Annals of Internal Medicine

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New drug target to treat pain from visceral organs

An approved drug for chronic constipation also relieves the pain associated with that condition. New research by Scott Waldman, MD, Ph.D., chair of pharmacology, physiology and cancer biology at Jefferson, demonstrates that the drug’s two actions can be separated biologically—a finding that may offer ways to precisely target visceral pain syndromes beyond constipation.

Here’s what was known: A called GUCY2C, present in the lining of the intestines, regulates water and salt balance, and therefore, the looseness of stools. The constipation medicine, called linaclotide, acts on this receptor to increase water secretion. However, the drug’s -relieving action does not appear to be a simple consequence of constipation relief, and hypotheses abounded as to how it all worked.

Dr. Waldman and his MD-Ph.D. student Joshua Barton sought to explore how the drug produced analgesia. The study, published in the Journal of Clinical Investigation focused on the GUCY2C receptor in a newly discovered intestinal cell type called neuropods, which can sense stimulation and communicate closely with neurons that send pain messages to the brain. The team partnered with neuroscientist Manuel Covarrubias, MD, Ph.D., who co-directed the study.

The researchers used molecular tools to delete GUCY2C receptors from neuropods in mice, but not from other intestinal cells. The altered animals experienced spontaneous visceral pain that the drug linaclotide did not relieve; meanwhile water secretion was unaffected. This finding, Dr. Waldman says, means that neuropod receptors are regulating sensory tone in the intestine and that they mediate the drug effect on pain.

What was most surprising, he says, is how stark the delineation was. Biological functions are known for redundancies and exploratory scientific research doesn’t often yield such clear results—in this case, separating two seemingly connected functions, pain relief and water secretion.

Dr. Waldman envisions therapies that directly target neuropod cells. “We may be able to side-step a major side effect—diarrhea—in other visceral pain conditions,” he says, such as with diarrhea or endometriosis. Visceral pain regulation by neuropods may represent “a final common pathway,” he says.

More information:
Joshua R. Barton et al, Intestinal neuropod cell GUCY2C regulates visceral pain, Journal of Clinical Investigation (2022). DOI: 10.1172/JCI165578

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Depression, anxiety tied to higher health care use with inflammatory bowel disease

Worsening or persistently high anxiety or depression symptoms are tied to significantly higher use of health care among patients with inflammatory bowel disease (IBD), according to a study published in the February issue of the American Journal of Gastroenterology.

Keeley Fairbrass, M.B.Ch.B., from University of Leeds in the United Kingdom, and colleagues assessed trajectories of mental health symptoms in IBD. The analysis included self-reported and health care utilization data from 1,031 adult outpatients with IBD.

The researchers found that patients with worsening or persistently abnormal anxiety or depression scores had increased antidepressant (28.6 versus 12.3 percent and 35.8 versus 10.1 percent for anxiety and depression, respectively) and opiate use (19.0 versus 7.8 percent and 34.0 versus 7.4 percent for anxiety and depression, respectively) compared with patients with persistently normal or improving scores.

Individuals with worsening or persistent symptoms were also more likely to have been diagnosed with IBD in the last 12 months and to have clinically active disease at baseline and lower quality-of-life scores. Furthermore, significantly more outpatient appointments, radiological investigations, and endoscopic procedures for IBD-related symptoms were required for individuals with worsening or persistently abnormal trajectories of anxiety or depression.

“Based on our findings, there is a clear need to offer formal psychological support to a subgroup of with IBD, through a defined referral pathway, to reduce health care utilization and, potentially, improve disease prognosis,” the authors write.

One author disclosed financial ties to the pharmaceutical industry.

Copyright © 2023 HealthDay. All rights reserved.

More information:
Keeley M. Fairbrass et al, Characteristics and Effect of Anxiety and Depression Trajectories in Inflammatory Bowel Disease, American Journal of Gastroenterology (2022). DOI: 10.14309/ajg.0000000000002063

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