IBS explained: causes, symptoms and treatment

IBS or irritable bowel syndrome is a common, chronic (long-term) condition that affects your large intestine. Although one in five adults in the UK have IBS, it is up to three times more common in women. It can start at any age but often begins in your teens or twenties. The effect on your lifestyle can be considerable, depending on the severity and frequency of your bouts of IBS. Here we’ll take a look at common causes and symptoms, as well as how you can manage your IBS.

IBS symptoms

One of the most common symptoms of IBS is stomach pain or cramps, which is often worse after eating and eases after opening your bowels. Other common symptoms include bloating, flatulence, diarrhoea, constipation, and/or small, hard stools that contain mucus. You may also experience nausea, fatigue, and difficulty controlling your bowel habits (bowel incontinence) and urination (urinary incontinence). 

These symptoms occur in both men and women. However, some women also experience pelvic pain and pain during sex, as well as more severe symptoms during certain phases of their menstrual cycle. Women with IBS may also have heavier and/or more painful periods.

When to see your doctor

IBS is not usually serious and doesn’t increase your risk of bowel cancer. However, it can have a significant effect on your quality of life. Many of the symptoms of IBS also overlap with other conditions affecting your bowel and in women, the reproductive organs — some of these conditions are serious and need treatment. 

If you are, therefore, concerned about your symptoms or struggling to manage your symptoms, see your GP. 

You should also seek your GP if you notice a hard lump or swelling in your abdomen, bleeding from your anus or bloody stools, or unexplained weight loss. 

Getting a diagnosis of IBS

There is no definitive test for IBS and consequently, diagnosis usually involves ruling out all other possible causes of your symptoms. 

Your doctor will ask you about your symptoms and medical history, and may perform a physical examination of your abdomen. They may then recommend one or several different tests to investigate other conditions that cause symptoms similar to IBS. This may include blood tests, stool tests and minimally invasive procedures, such as a flexible sigmoidoscopy to examine the lower part of your colon or a colonoscopy to examine your entire colon. 

Both a flexible sigmoidoscopy and a colonoscopy involve passing a thin, flexible, telescope-like tube with a camera and a light at the end into your colon via your back passage (rectum). This allows your doctor to see the inside of your colon to detect abnormalities. 

These tests can help rule out other digestive system conditions such as diverticulitis, inflammatory bowel disease, which includes Crohn's disease and ulcerative colitis, coeliac disease and infections of your gut. Pancreatitis can also cause IBS-like symptoms and may need to be ruled out. 

Investigating IBS in women

In women, there are other conditions relating to your reproductive organs that can cause IBS-like symptoms, such as endometriosis and ovarian cancer. Depending on your symptoms, your doctor may need to rule out these conditions too. 

Investigating the possibility of ovarian cancer can involve blood tests, a vaginal and/or abdominal ultrasound scan, and a minimally invasive procedure to collect a tissue sample (biopsy), such as a needle biopsy or laparoscopy. 

Investigating the possibility of endometriosis can involve a pelvic examination, blood tests, a pelvic ultrasound scan and a laparoscopy.

Types of IBS

IBS can be divided into three main categories based on your symptoms. The most common type of IBS is IBS-C, where C stands for constipation. IBS-C refers to IBS that triggers more bouts of constipation than it does diarrhoea. In contrast, IBS-D refers to IBS that causes more bouts of diarrhoea than it does constipation. IBS-M refers to IBS that causes mixed bowel habits ie on days where you have disturbed bowel habits, at least a quarter of your bowel movements are constipated and at least a quarter are diarrhoea.

What causes IBS?

The causes of IBS aren’t fully understood but several risk factors have been identified, including stress, anxiety, depression and a family history of IBS. As already mentioned, IBS is more common in women. Your risk also increases if you have diverticulitis or an infection of your gut, such as gastroenteritis. 

Certain foods can trigger or worsen IBS symptoms, including highly processed foods, fried foods, dairy products (with the exception of yoghurt), caffeine, fizzy drinks, foods high in fructose and foods containing the sugar alternatives sorbitol or xylitol (eg sugar-free chewing gum). 

Certain medications can also trigger or worsen IBS symptoms, including antibiotics, certain antidepressants and medications containing sorbitol (eg ibuprofen).

Treating IBS

There is no cure for IBS but there are things you can do to help manage and relieve your symptoms. 

During a bout of IBS, applying a heat pack or a hot water bottle wrapped in a towel to your abdomen can help relieve pain and reduce muscle spasms. Drinking certain types of tea can help reduce bloating — certain teas can aggravate your symptoms, so stick to IBS-friendly teas, such as peppermint tea, fennel tea and anise tea. As stress can trigger or worsen a bout of IBS, relaxation techniques can be helpful to prevent or relieve your symptoms eg yoga, meditation and deep breathing exercises. 

You can also help to prevent or reduce the severity of a bout of IBS by identifying foods that trigger it. Some people find that foods high in FODMAPs (fermentable oligo-, di-, monosaccharides, and polyols) trigger a bout of IBS. 

Keep a food diary and speak to your GP or a dietitian about how to avoid foods that you think are triggering your symptoms — to make sure your diet is still healthy and balanced, they may suggest alternatives or substitutes for the foods identified. 

Eating smaller meals more often, sticking to a regular mealtime schedule, exercising regularly, trying probiotics and quitting smoking can all help relieve IBS too. 

Medication and psychological therapies

If lifestyle changes aren’t effective or don’t provide enough relief from your symptoms, you can speak to your GP about other strategies, which may include medication. Your doctor may recommend taking an anti-spasmodic drug to relieve abdominal cramps, bile acid binders to reduce diarrhoea, osmotic laxatives to resolve constipation or certain antidepressants that are known to relieve IBS symptoms (eg citalopram or amitriptyline).

If medication doesn’t help manage your IBS and/or stress, anxiety or depression are thought to be contributing to your symptoms, your doctor may suggest therapies targeting your mental health. This may include biofeedback, cognitive behavioural therapy (CBT) and hypnotherapy.