Irritable bowel syndrome: Symptoms, diagnosis & treatment

woman with ibs holding her stomach in pain
(Image credit: Getty Images)

Wondering whether you have irritable bowel syndrome (IBS)? Everyone struggles with digestive issues from time to time. It’s common to experience stomach cramps before an important exam or feel discomfort after eating something that didn’t agree with you. But when the digestive symptoms become part of your daily routine, you may indeed be suffering from IBS. 

Studies suggest that up to 21% of the general population may have this condition, including around 12% of people in the US. Irritable bowel syndrome is a chronic disorder that affects the large intestine. Although it’s not life-threatening, it markedly impacts a person’s quality of life. Symptoms tend to happen irregularly, and include stomach cramps, bloating, diarrhea and constipation. IBS flare-ups are managed with diet, lifestyle changes and counseling. More severe cases may also be treated with medications.

It may be difficult to recognise whether your symptoms match the diagnostic criteria of irritable bowel syndrome. Here, we discuss the tell-tale signs of this condition, as well as possible treatment options, to give you a better understanding of IBS and how to prevent its unpleasant symptoms. If you think you may be suffering from IBS, it is important to consult your doctor.   

What is irritable bowl syndrome (IBS)?

According to the National Institute of Diabetes and Digestive and Kidney Diseases, IBS is a group of digestive symptoms, such as repeated pain in your abdomen, diarrhea, constipation and bloating. Most people suffering from this condition will have normal bowel movements on some days, and experience unpleasant symptoms on other days. As opposed to Inflammatory Bowel Disease (IBD), IBS does not damage the digestive tract and it’s not life-threatening. 

Irritable Bowel Syndrome is a disorder of gut-brain interactions, meaning it’s a condition related to problems with how the brain and the gut communicate and work together. When this connection is disrupted, the gastrointestinal tract becomes more sensitive and changes how the muscles in your bowel contract. Changes in the bowel movements trigger the onset of digestive symptoms. 

Irritable bowel syndrome may be closely linked to the functioning of the nervous system. As scientists from the Alimentary Pharmacology & Therapeutics point out, people with IBS are likely to also suffer from conditons like anxiety, depression, fibromyalgia, chronic fatigue syndrome, sexual dysfunction and sleep problems. 

There are three types of IBS, based on the symptoms that you experience the most.   

  • IBS with constipation (IBS-C): on days when you have at least one abnormal bowel movement, most of your stools are hard and lumpy. 
  • IBS with diarrhea (IBS-D): on days when you have at least one abnormal bowel movement, most of your stools are loose and watery. 
  • IBS with mixed bowel habits (IBS-M): on days when you have at least one abnormal bowel movement, your stools are both hard and watery on the same day. 

Different IBS types may require different medications or treatments.  

IBS: Causes and symptoms

According to the National Institute of Diabetes and Digestive and Kidney Diseases, symptoms of IBS include pain in your abdomen and changes in your bowel movements. These changes may be diarrhea, constipation, or both, depending on what type of IBS you have. Other symptoms may include bloating, discomfort and mucus in your stool. In some people with IBS, food may move too slowly or too quickly through the digestive tract. Others may feel pain when a normal amount of gas or stool is in the gut.

Scientists are not sure what exactly causes irritable bowel syndrome. Many suggest that there isn’t a single factor, but rather a specific combination of problems that leads to this condition. Some factors can cause IBS in one person, but may not trigger it in other people.  

woman suffering from irritable bowel syndrome

(Image credit: Getty Images)

It’s been established that women are up to two times more likely than men to develop IBS. According to a review published in the Frontiers of Endocrinology, this could be down to female sex hormones and how they impact bowel movements, digestion, and mental wellbeing. Many women experience more severe symptoms when they are on their periods. 

Many studies have shown that there is a strong link between IBS and difficult early life events, such as physical or sexual abuse. Chronic psychological stress has a wide-ranging and long-lasting impact on our nervous, hormonal and immune systems, as well as our gut health. Moreover, stressful events are known to cause or exaggerate IBS flare-ups. Irritable Bowel Syndrome also tends to be closely connected to depression, anxiety and somatic disorders. According to a review published in the Current Opinion in Endocrinology, Diabetes, and Obesity journal, mood disorders change the composition of gut microbiota, increasing the severity of IBS symptoms. 

Bacterial infections or bacterial overgrowth in your digestive tract may also trigger IBS. As scientists from the Journal of Alimentary Pharmacology and Therapeutics point out, you’re six times more likely to develop IBS after acute gastrointestinal infection.  

IBS: Diagnosis

There are several steps needed to diagnose IBS. First, your doctor will discuss your medical history, ask about your experiences and look for a certain pattern in your symptoms. They will consider IBS diagnosis if you have pain in your abdomen along with two or more of the following symptoms:

  • Your pain is linked to changes in your bowel movements.  
  • You notice a change in how often you have a bowel movement.
  • You notice a change in the way your stools look  

Your doctor may diagnose IBS if you’ve had symptoms at least once a week in the last three months and your symptoms first started at least six months ago. Before moving on to the physical exam, they will try to rule out other possible health problems. If your symptoms also include anemia, bleeding from your rectum, bloody stools and weight loss, you may be suffering from a different gastrointestinal disease.

During a physical exam, your doctor will check for bloating, listen to the sounds within your abdomen using a stethoscope and check your abdomen for tenderness or pain. Sometimes, more tests may be needed. 

IBS: Treatment

Diet

Dietary modifications remain the primary treatment for IBS. In particular, a diet low in so-called FODMAPs (a group of fermentable short-chain carbohydrates and sugars) seems to be effective. According to scientists from the Annual Review of Medicine journal, 52-86% of patients report significant improvement of their IBS symptoms after following the low FODMAP diet

Examples of IBS trigger foods rich in FODMAPs include: 

  • Fruits like apples, apricots, blackberries, cherries, mango, nectarines, pears, plums, and watermelon, or juice containing any of these fruits 
  • Vegetables like artichokes, asparagus, beans, cabbage, cauliflower, garlic, lentils, mushrooms and onions 
  • Dairy products
  • Wheat and rye
  • Honey
  • Processed foods high in high-fructose corn syrup
  • Products with sweeteners ending in “–ol,” such as sorbitol, mannitol, xylitol, and maltitol 

foods on a low FODMAP diet

(Image credit: Getty Images)

Nevertheless, not every IBS sufferer will react to the same trigger foods. Your doctor or dietician may suggest that you first try the low FODMAP diet for a few weeks to see if it helps with your symptoms. If your symptoms improve, they may recommend slowly adding particular foods that contain FODMAPs back into your diet. This trial and error approach will help you find out if there are any foods with FODMAPs that you can eat without having IBS symptoms. 

Probiotics and prebiotics

Gut-brain interactions are the key to IBS. To keep the gut health in check and help with the IBS symptoms, many medical professionals recommend supplementation with probiotics and prebiotics. Multiple studies have shown that taking probiotics can help reduce stomach pain and regulate bowel movements. And according to a meta-analysis published in The American Journal of Gastroenterology, eating enough soluble prebiotic fiber can be effective in the management of IBS. 

Medications

Irritable bowel syndrome tends to be managed with lifestyle modifications. However, certain medications can help with easing severe flare-ups. As mentioned in the Digestion journal, the treatment type depends on the type of IBS. For IBS-D, doctors may prescribe a drug called eluxadoline. Whereas for IBS-C, you may be advised to take linaclotide, lubiprostone and plecanatide. According to an article published in The American Journal of Medicine, plecanatide may be particularly safe and effective in reducing IBS-related constipation. 

Mental health

Given the strong links between IBS and mental health, medical professionals are increasingly recommending strategies that help with stress and mood disorders. According to The World Journal of Gastroenterology, IBS symptoms can improve with antidepressants, antipsychotics, and medications that regulate the levels of 5-HT (the precursor for serotonin - a mood stabilizing neurotransmitter). There’s also some evidence that meditation and yoga could be useful tools for managing Irritable Bowel Syndrome.  

Fecal microbiota transplantation  

Fecal microbiota transplantation (FMT), also known as a stool transplant, is the process of transferring fecal microbes from one individual to another. FMT is a relatively new therapy, but so far the results are promising. According to scientists from the Expert Review of Gastroenterology & Hepatology journal, stool transplants may reduce IBS symptoms in about 70% of patients, and it does not tend to produce any serious side effects. This procedure is also relatively easy and inexpensive. However, more studies are needed before fecal microbiota transplantation can be used as a routine therapy. 

This article is for informational purposes only and is not meant to offer medical advice.

Additional resources

Anna Gora
Health Writer

Anna Gora is a health writer at Live Science, having previously worked across Coach, Fit&Well, T3, TechRadar and Tom's Guide. She is a certified personal trainer, nutritionist and health coach with nearly 10 years of professional experience. Anna holds a Bachelor's degree in Nutrition from the Warsaw University of Life Sciences, a Master’s degree in Nutrition, Physical Activity & Public Health from the University of Bristol, as well as various health coaching certificates. She is passionate about empowering people to live a healthy lifestyle and promoting the benefits of a plant-based diet.