Irritable Bowel Syndrome (IBS)

David Walji, BHSc, MD(c)

May 11

7 min read

Irritable Bowel Syndrome (IBS) is a long-term condition that affects the way that your stomach and intestines work. It causes belly pain and changes in people’s bathroom habits but does not lead to bowel damage or turn into cancer [1–3].

What is IBS?

IBS is a common disorder that is a result of gut-brain miscommunication. Normally, these two organs communicate through nerves and chemicals, but in IBS, these pathways are disrupted, which may result in the intestines spasming or becoming very sensitive [4]. IBS will show up as repeated pain and problems with pooping, such as diarrhea (IBS-D), constipation (IBS-C), both (IBS-M), or unclassified (IBS-U) [1–4].

What Causes IBS?

There isn’t just one cause of IBS. Instead, it happens when a few different things in the body don’t work quite the way they should [5–7].

The gut and brain aren’t on the same page
Your brain and intestines are always talking to each other. In IBS, these signals can get mixed up. This can make the gut move too fast (causing diarrhea) or too slow (causing constipation) [5–7].
A more sensitive gut
People with IBS often have a sensitive stomach. Even normal amounts of gas or stool can feel painful or cause bloating. This is known as visceral hypersensitivity [5–7].
Changes in gut bacteria
Your intestines are full of healthy bacteria that help with digestion. In IBS, this balance may be different. Some people develop IBS after a bad stomach infection, like food poisoning [5–7].
Irregular gut movement
The muscles in your intestines help move food along. In IBS, this movement can be too quick or too slow, leading to symptoms. This is known as intestinal dysmotility [5–7].
Food triggers
Certain foods can make symptoms worse. Common triggers include dairy, wheat, beans, cabbage, and fizzy drinks. This doesn’t usually mean a true allergy, just a sensitivity [5–7].
Stress and emotions
Stress doesn’t cause IBS, but it can make symptoms worse. The gut is closely connected to how we feel. Past stress, especially earlier in life, may also increase the risk of IBS [5–7].

Common Symptoms of IBS

Common symptoms of IBS include, but are not limited to:

Belly pain or cramping [8]
Bloating and gas [8]
Diarrhea, constipation or a combination of the two [8]
Mucus (whitish slime) appearing in poop [9,10]
Feeling like the bowel doesn’t empty completely [9,10]
Tiredness, nausea, heartburn [9,10]

IBS symptoms can be different from one person to the next [9,10]. They can last long periods of time or can occur in short bursts [9,10]. Symptoms will also often flare up after meals, when people are stressed, or at certain times in people’s menstrual cycle (see Menstrual Cycle Basics) [9,10].

Who Is at Risk for IBS?

Women are diagnosed almost twice as much as men are [11].
People under 50 also have a higher risk of getting IBS [11].
People taking hormonal therapies, such as estrogen therapy, may be at higher risk [11].
Having a close relative with IBS increases your chances [11].
A history of anxiety, depression or a history of abuse have all been linked to IBS [11].
Severe stomach infections or sensitivity to certain foods may lead to IBS [11].
Other chronic pain disorders like fibromyalgia can occur alongside IBS [12,13].

How Is IBS Diagnosed?

There is no single test for IBS. Doctors diagnose it based on your symptoms and by excluding other conditions.

The Rome IV criteria helps doctors to make the diagnosis. The criteria includes the following:

You have had belly pain at least one day per week for the past three months.
The pain is linked to at least two of the following:
Pain improves or worsens with bowel movements
There is a change in how often you go to the bathroom
Or there is a change in the appearance of stool.
Symptoms started at least six months before diagnosis [2,3].

Your doctor may also ask about features such as weight loss, bleeding or waking up at night to rule out other conditions. Tests like blood work, stool tests, hydrogen breath tests or a colonoscopy may be done to rule out infections, celiac disease or inflammatory bowel disease.

Treatment Options: Lifestyle Management

There is no cure for IBS, but most people can control symptoms by changing their diet, habits and stress levels.

Keeping a symptom and food diary by writing down what you eat and when IBS symptoms occur can help to identify different types of triggers [14].

Eating more soluble fibre such as from fruits and vegetables can help with constipation [14]. Be sure to introduce fibre slowly and drink plenty of water to make this work effectively [9].

Trying a low‑FODMAP diet will limit certain carbohydrates that might be difficult to digest [14]. When in doubt, work with a dietitian for guidance [14].

Avoiding common triggers such as dairy, beans, cabbage and carbonated drinks as well as chewing food slowly or starting on a gluten‑free diet can also help [9,10].

It’s also important to aim for at least 150 minutes per week of moderate exercise, to manage stress with practices like deep breathing or yoga and to make sure to get seven to nine hours of sleep each night [9].

Treatment Options: Medical Management

There is no direct medication to treat IBS but individual symptoms can be dealt with on a case-by-case basis.

Depending on your main problem, doctors may suggest laxatives or fibre supplements for constipation, anti‑diarrheal medicines like loperamide for diarrhea, or antispasmodic medicines to relax gut muscles [15].

Antidepressants can also relieve pain and improve mood [15]. Cognitive behavioral therapy, hypnotherapy or biofeedback can help manage stress and reduce gut sensitivity [15].

Some people find relief with probiotic supplements, but evidence is still emerging on this topic [15].

Can You Prevent IBS?

Because the exact cause of IBS is unknown, there is no sure way to prevent it [9]. However, you can lower the chance of symptom flare‑ups by

Eating regular and balanced meals
Drinking plenty of water and staying active
Managing stress through relaxation and good sleep
Seeking help early if you notice ongoing changes in bowel habits.
Early diagnosis and education can prevent unnecessary tests and complications [16]

When to Seek Medical Advice

If your symptoms last more than three months or if they interfere with daily life, consider reaching out to a health professional [9]. Contact a doctor right away if you have any of the following alarm signs:

Unexplained weight loss or fever [9]
Vomiting or rectal bleeding [9]
Diarrhea so severe it wakes you from sleep [9]
Severe or constant abdominal pain that does not improve after passing gas or stool [9]

Frequently Asked Questions (FAQs)

Is IBS the same as inflammatory bowel disease (IBD)?

No. IBS is a functional disorder, meaning the bowel looks normal but doesn’t work properly. IBD, like Crohn’s disease or ulcerative colitis, involves inflammation and damage to the intestines and can lead to complications like bleeding or weight loss.

Does IBS turn into cancer?

No. IBS does not cause changes in bowel tissue or increase the risk of colon cancer.

Is IBS permanent?

IBS is usually a long‑term condition with symptoms that come and go. While there is no cure, most people can control their symptoms with lifestyle changes and treatment.

Can children get IBS?

Yes. IBS can affect people of any age, though it is more common in late teens to early adulthood. If your child has ongoing stomach pain or changes in bowel habits, talk to a doctor.

What foods trigger IBS?

Common triggers include dairy products (if lactose intolerant), wheat or gluten, beans, cabbage, onions, carbonated drinks and fatty or spicy foods. Triggers vary between people; keeping a food diary helps identify yours.

Are probiotics helpful for IBS?

Research is mixed. Some people find probiotics may ease symptoms, but not all products work the same. Talk to your healthcare provider before starting any supplement.

Sources:

Nørgaard M, Farkas DK, Pedersen L, Erichsen R, de la Cour ZD, Gregersen H, et al. Irritable bowel syndrome and risk of colorectal cancer: a Danish nationwide cohort study. Br J Cancer. 2011 Mar 29;104(7):1202–6. doi:10.1038/bjc.2011.65 PubMed PMID: 21343936; PubMed Central PMCID: PMC3068503.
Longstreth GF, Thompson WG, Chey WD, Houghton LA, Mearin F, Spiller RC. Functional Bowel Disorders. Gastroenterology. 2006 Apr;130(5):1480–91. doi:10.1053/j.gastro.2005.11.061
Lacy BE, Mearin F, Chang L, Chey WD, Lembo AJ, Simren M, et al. Bowel Disorders. Gastroenterology. 2016 May;150(6):1393-1407.e5. doi:10.1053/j.gastro.2016.02.031
Konturek PC, Brzozowski T, Konturek SJ. STRESS AND THE GUT: PATHOPHYSIOLOGY, CLINICAL CONSEQUENCES, DIAGNOSTIC APPROACH AND TREATMENT OPTIONS.
Chey WD, Kurlander J, Eswaran S. Irritable Bowel Syndrome: A Clinical Review. JAMA. 2015 Mar 3;313(9):949–58. doi:10.1001/jama.2015.0954
Tang HY, Jiang AJ, Wang XY, Wang H, Guan YY, Li F, et al. Uncovering the pathophysiology of irritable bowel syndrome by exploring the gut-brain axis: a narrative review. Ann Transl Med. 2021 Jul;9(14):1187–1187. doi:10.21037/atm-21-2779
Aggeletopoulou I, Papantoniou K, Pastras P, Triantos C. Unraveling the Pathophysiology of Irritable Bowel Syndrome: Mechanisms and Insights. Int J Mol Sci. 2025 Jan;26(21):10598. doi:10.3390/ijms262110598
Lovell RM, Ford AC. Global Prevalence of and Risk Factors for Irritable Bowel Syndrome: A Meta-analysis. Clin Gastroenterol Hepatol. 2012 Jul 1;10(7):712-721.e4. doi:10.1016/j.cgh.2012.02.029
Cleveland Clinic. Irritable bowel syndrome (IBS). Cleveland (OH): Cleveland Clinic; 2025. Available from: https://my.clevelandclinic.org/health/diseases/4342-irritable-bowel-syndrome-ibs
Mayo Clinic. Irritable bowel syndrome: symptoms and causes. Rochester (MN): Mayo Foundation for Medical Education and Research; 2025. Available from: https://www.mayoclinic.org/diseases-conditions/irritable-bowel-syndrome/symptoms-causes/syc-20360016
Black CJ, Ford AC. Global burden of irritable bowel syndrome: trends, predictions and risk factors. Nat Rev Gastroenterol Hepatol. 2020 Aug;17(8):473–86. doi:10.1038/s41575-020-0286-8
Castro Sánchez AM, García López H, Fernández Sánchez M, Pérez Mármol JM, Aguilar-Ferrándiz ME, Luque Suárez A, et al. Improvement in clinical outcomes after dry needling versus myofascial release on pain pressure thresholds, quality of life, fatigue, pain intensity, quality of sleep, anxiety, and depression in patients with fibromyalgia syndrome. Disabil Rehabil. 2019 Sep 11;41(19):2235–46. doi:10.1080/09638288.2018.1461259 PubMed PMID: 29681188.
Mayer EA, Ryu HJ, Bhatt RR. The neurobiology of irritable bowel syndrome. Mol Psychiatry. 2023 Apr;28(4):1451–65. doi:10.1038/s41380-023-01972-w
Lacy BE, Pimentel M, Brenner DM, Chey WD, Keefer LA, Long MD, et al. ACG Clinical Guideline: Management of Irritable Bowel Syndrome. Off J Am Coll Gastroenterol ACG. 2021 Jan;116(1):17. doi:10.14309/ajg.0000000000001036
Camilleri M. Diagnosis and Treatment of Irritable Bowel Syndrome: A Review. JAMA. 2021 Mar 2;325(9):865–77. doi:10.1001/jama.2020.22532
Nathani RR, Sodhani S, Goosenberg E. Irritable Bowel Syndrome. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2026 [cited 2026 Mar 19]. Available from: http://www.ncbi.nlm.nih.gov/books/NBK534810/ PubMed PMID: 30521231.

Are you still confused or do you still have questions?

Leave us Feedback!

Medical Disclaimer: HealthDecoded content is for education only and does not replace professional medical advice. Always seek guidance from a qualified healthcare provider.