Millions Misdiagnosed with IBS May Actually Have SIBO, Experts Warn
A significant number of individuals suffering from chronic digestive issues could be incorrectly diagnosed with Irritable Bowel Syndrome (IBS), potentially leading to serious health complications. Experts are raising concerns that a condition known as Small Intestinal Bacterial Overgrowth (SIBO) is on the rise and often mistaken for IBS. This misdiagnosis can delay or prevent access to effective treatments, putting patients at risk of nutritional deficiencies, kidney problems, and even certain types of cancer.
SIBO occurs when an excessive amount of bacteria colonises the small intestine, a part of the digestive system that should typically harbour very few microbes. This overgrowth leads to a range of uncomfortable symptoms, including diarrhoea, bloating, and excessive gas, which unfortunately mirror those of IBS. In some cases, patients have even been told their symptoms are psychological and have been prescribed antidepressants instead of receiving appropriate medical attention for SIBO.
Understanding SIBO: What’s Happening in Your Gut?
Professor David Sanders, a leading expert in gastroenterology, explains the normal digestive process. “When we eat food, our stomach acid destroys most of the bacteria before it reaches the small intestine,” he states. The remaining contents then move into the large intestine, which is home to a healthy community of beneficial bacteria known as the gut microbiome. This microbiome plays a crucial role in producing essential vitamins and breaking down complex nutrients like fibre.
However, in individuals with SIBO, bacteria migrate into the small intestine. As food travels through this section, these bacteria ferment it, producing gas as a byproduct. This fermentation process is the primary cause of the pain, bloating, and discomfort experienced by SIBO sufferers.
Factors Contributing to SIBO Development
Experts identify several reasons why SIBO might develop, many of which are linked to the body’s ability to properly digest food and move it through the digestive tract.
Reduced Stomach Acid: Individuals who naturally produce less stomach acid, or those taking Proton Pump Inhibitors (PPIs) for heartburn, are at higher risk. Stomach acid is vital for killing bacteria ingested with food. PPIs, commonly prescribed for acid reflux, can significantly reduce stomach acid levels. Professor Sanders highlights, “We need acid to kill the bacteria that’s on whatever we eat.” Astonishingly, one in five people in the UK have taken a PPI, with prescriptions rising dramatically over the last two decades, a trend potentially exacerbated by poor dietary habits.
Anatomical Abnormalities: Structural issues within the intestines can also predispose individuals to SIBO. Professor Sanders explains, “Anyone with an anatomical defect that creates little pouches and cul de sacs, where bacteria can hide, instead of moving through the gut, are more likely to develop SIBO.” These abnormalities can be the result of previous surgeries or conditions like diverticulosis, which creates small pouches in the intestinal walls where bacteria can proliferate.
Slowed Gut Motility: When food moves too slowly through the intestines, it gives bacteria more time to ferment and multiply. Professor Sanders notes, “Anything that slows down gut transit gives bacteria a sporting chance of getting hold.” This can affect various groups, including:
- Women who have given birth via C-section.
- Individuals with diabetes.
- The elderly.
- Users of weight-loss injections, as these medications work by slowing down the digestive process.
- There is also emerging evidence suggesting that food poisoning can contribute to SIBO by disrupting normal gut function and slowing digestion.
Recognising the Symptoms of SIBO
The symptoms of SIBO can be varied and often overlap with other digestive conditions. However, key indicators include:
- Bloating
- Abdominal distension
- Excessive gas
- Frequent flatulence
- Diarrhoea
- Unexplained weight loss
Diarrhoea and bloating are considered particularly important symptoms that should prompt further investigation for SIBO.
Foods to Consider Avoiding with SIBO
For individuals diagnosed with SIBO, certain foods can exacerbate symptoms by promoting fermentation. While dietary adjustments are often a key part of management, it’s crucial to work with a healthcare professional to create a personalised plan. Commonly identified trigger foods include:
- Onions
- Garlic
- Alcohol
- Sugar alcohols (e.g., xylitol, sorbitol)
- Honey
- Beans and pulses
- Fizzy drinks
- Apples
- Wheat
- Dairy
Diagnosis and Treatment of SIBO
Diagnosing SIBO typically involves ruling out more serious conditions like bowel cancer. While a stool test and gastroscopy (a procedure where a camera is inserted down the throat) are considered definitive, they are invasive. A less invasive, though less reliable, method is a breath test. This test involves the patient consuming a sugary solution, and then their breath is analysed for levels of hydrogen and methane gas, which are produced by bacterial overgrowth.
However, Professor Sanders cautions about the reliability of breath tests: “This is very controversial in the world of gastroenterologists, because the result is affected by the motility of the gut.” If the solution moves too quickly through the small intestine and reaches the large intestine prematurely, it can lead to a false positive result. This unreliability has led to differing opinions among experts, with some believing SIBO is widely underdiagnosed, while others suggest it may be over-diagnosed.
The primary treatment for SIBO is a course of the antibiotic rifaximin. Research indicates that this medication can effectively eliminate the bacterial overgrowth in the small intestine. While it’s a relatively inexpensive tablet, taken three times daily for two to eight weeks, it’s not without risks. It can also eliminate beneficial gut bacteria, potentially leading to other health issues.
However, leaving SIBO untreated can have serious consequences. Studies, including one from 2016 involving over 200 cancer patients, have found a significant association between SIBO and the development of pancreatic, bile duct, and colon cancers.
Alongside antibiotics, herbal antimicrobials such as berberine and oregano have shown promise, particularly when initial treatments are unsuccessful.
The Importance of Dietary Management and Addressing Underlying Causes
Effective SIBO management often involves addressing gut fermentation through dietary changes. The low FODMAP diet is commonly recommended. FODMAP stands for Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols – a group of carbohydrates that are poorly absorbed in the small intestine and can ferment, triggering SIBO symptoms. This diet involves limiting foods like wheat, beans, pulses, milk, and apples. The ultimate goal, however, is to gradually reintroduce food groups to help patients identify personal triggers and achieve a more balanced diet.
Probiotics may also play a role in restoring the delicate balance of the gut microbiome, though they are not a specific treatment for SIBO itself.
Crucially, experts agree that addressing any underlying causes of SIBO is paramount for long-term success. This might involve consulting with a doctor about discontinuing PPIs or working on strategies to improve gut motility. By increasing awareness and encouraging a thorough diagnostic approach, healthcare professionals aim to ensure that individuals with SIBO receive the correct diagnosis and effective treatment, safeguarding their health and well-being.
