There are three types of IBS: IBS with constipation (IBS-C), IBS with diarrhea (IBS-D) and IBS with mixed bowel habits (IBS-M). Whether you can’t go or you go too much, the bloating, cramps, gas and other bathroom-related problems are no fun — especially since they’re chronic and can worsen anxiety and depression.
There’s no single definitive cause of IBS, though you might’ve heard about stress being a factor. While this is true, there are some other, lesser-known contributors to IBS. Below, experts break down what they are:
Small intestinal bacterial overgrowth (SIBO)
SIBO is when you have too much bacteria in your small intestine, which affects your overall digestion. Although SIBO and IBS are “different medical conditions, they commonly coexist,” Marilia Chamon, a registered nutritionist, gut health specialist and founder of Gutfulness, told HuffPost.
Chamon pointed to a small study that found 78% of people with IBS had overgrowth of bacteria, and eliminating it helped 48% of those individuals. Another study backed this up, noting that proper treatment may help gastrointestinal symptoms improve in people with both SIBO and IBS.
Next steps: Not sure if SIBO is a contributing factor for you or not? Dr. James Lee, a gastroenterologist with Providence St. Joseph Hospital in California, said that it “can be identified by noninvasive breath tests,” and that “effective treatments are available once diagnosed.”
Ask your gastro or primary care doctor if you qualify for a diagnostic test. If you do have SIBO, treatments such as surgery, antibiotics and nutritional supplements can help. Some signs you may want to get that breath test include bloating, pain, cramps, constipation, diarrhea, multiple food sensitivities, improvement in symptoms with the use of antibiotics, and vitamin B12 and iron deficiencies, according to Chamon.
Some people may have infections and not even realize it.
“A much less known cause is suffering from an acute gastrointestinal infection,” said Dimitar Marinov, an assistant professor at the Medical University of Varna, Bulgaria. While there isn’t exact data on how common this is, Marinov pointed to data that suggests post-infection IBS (or PI-IBS) may play a role in up to 32% of IBS cases.
Although the mechanisms that lead to PI-IBS aren’t fully understood, Marinov said inflammation and changes in the gut are believed to be among them.
Lee said infections such as Campylobacter and Giardia specifically can cause people to develop IBS symptoms.
“After the acute episode of infection is over, these patients develop possible autoimmune responses, leading to diarrhea and bloating as well as pain,” he told HuffPost.
Next steps: You treat PI-IBS the same way you’d treat regular IBS: stress management, pain management, therapy and even antidepressants. You also want to make sure you’re controlling any acute infection. For Campylobacter and Giardia, the main thing to do is stay hydrated. Symptoms include having diarrhea, experiencing abdominal cramps, needing “to go” more often, seeing blood or mucus in your stool and losing weight, Marinov said. Talk to your doctor ASAP if you experience any of this, especially if your symptoms start to worsen.
What you eat — and eating disorders
Diet can be a major contributor of IBS symptoms, so it’s one to be aware of. But which foods are the worst triggers? Wheat, dairy, eggs and beans, per Lee.
However, cutting out entire food groups can lead to eating disorders. In fact, up to 98% of people with eating disorders meet the criteria for functional gastrointestinal disorders, the most common of which is IBS. So here comes the chicken-and-egg question: Which comes first? This study, which involved a sample size of more than 230 participants, suggests eating disorders can increase the risk of developing IBS.
Next steps: Lee said a low-FODMAP diet is often recommended for people with IBS. Foods you can eat on that diet include almond milk, rice, oats, potatoes, cucumbers, zucchini, oranges, strawberries, pineapple and more.
The FODMAP diet encourages you to stop eating high-FODMAP foods such as onions, garlic, apples, peaches and others, then slowly reintroduce them so you can see which ones cause symptoms.
Since this diet can be triggering — a 2019 study showed that greater adherence to a low-FODMAP diet is associated with eating disorder behavior — talk to a therapist, doctor or dietitian who can assess you for eating disorder risk first or give you a healthier plan instead.
Low thyroid function
Your thyroid is a gland in your neck that releases hormones, which regulate bodily functions. So if it’s not working as it should, other functions — like going to the bathroom — won’t be working so well, either.
“When it becomes underactive, it decreases gastrointestinal mobility and slows down transit time, resulting in constipation,” Chamon said of the thyroid. “In addition, decreased gastrointestinal motility can also result in SIBO, and studies have found that over 50% of individuals with hypothyroidism tested positive for SIBO.”
Next steps: If you’ve been diagnosed with IBS-C or IBS-M, running a thyroid panel might be worth it, Chamon said, especially if you’re having other thyroid-related symptoms. These include being sensitive to the cold, slow movements and thoughts, muscle aches, dry skin, brittle nails, irregular or heavy periods, loss of libido and more. While there’s some mixed evidence on whether treating thyroid issues will improve IBS symptoms, a physician will be able to determine your best course of treatment for both problems. Your doctor may decide to put you on specific supplements to help improve your thyroid, or they may offer another plan.
IBS causes a lot of painful, annoying and, uh, undesirable symptoms, but knowing these “hidden” issues and implementing a combination of at-home treatments and fixes from the doc can help you manage it better.