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Bowled Over By Your Bowel: IBS Causes, Risk Factors and Treatments

Medically reviewed by Carmen Fookes, BPharm. Last updated on Feb 10, 2022.

What is Irritable Bowel Syndrome (IBS)?

It is actually easier to say what Irritable Bowel Syndrome (IBS) is NOT, than to define what it actually is.

This is because symptoms of IBS are similar to countless other conditions - such as endometriosis, giardiasis, food allergies, inflammatory bowel disease, ulcerative colitis....the list goes on and on. Most of these conditions need to be excluded before a definite diagnosis of IBS can be made.

According to the American College of Gastroenterology, IBS is defined as a chronic, often debilitating, and highly prevalent disorder of gut-brain interaction.

Symptoms of IBS Include Altered Bowel Habits and Stomach Pain

Symptoms of IBS vary a lot. Even in the same person, IBS symptoms may change from month-to-month. Most people with IBS have at least two of these symptoms:

  • Multiple episodes of stomach discomfort for at least three months of the past year
  • Altered bowel habits - passing feces more or less frequently than normal or periods of constipation and then periods of diarrhea
  • Pain or discomfort that lessens after a bowel movement
  • Mucus mixed in with the feces
  • Swelling or bloating of the stomach, or a feeling of fullness soon after eating.

Increased stomach gurgling or bowel sounds are also reported frequently by people with IBS.

How Hard is IBS to Diagnose?

Short answer: IBS is difficult to diagnose!

It takes most people three years and at least three different doctors before they are given a diagnosis of IBS. Part of the difficulty with diagnosis rests with the many different presentations of IBS. Some people are more likely to have constipation (constipation-predominant IBS or IBS-C), others diarrhea (diarrhea-predominant IBS or IBS-D), while a few experience both constipation and diarrhea at different times (mixed IBS).

To add to the confusion, symptoms are generally not stable over a lifetime and can change without warning.

Why Did it Happen to Me?

Nobody knows what causes IBS but there are certain risk factors that make you more likely to get the condition.

IBS is twice as likely to occur in women than men and more common in people under age 45. If you have a family member with the disorder, you are also at higher risk of getting it. Psychological stress, caused by anxiety, depression, personality disorder, or a history of sexual abuse can bring on IBS.

IBS has also been associated with smoking.

How Much of a Role Does Diet Play in IBS?

Around 30-50% of IBS sufferers relate their symptoms to food allergies or food intolerances. However, trials have found that only 1 in 5 people reacted when given these presumed offending foods in a blinded manner.

Even more surprising is the lack of good quality research around diet and IBS. Gluten exacerbated symptoms in 68% of IBS sufferers in one trial compared with the 40% who were on a gluten-free diet. In another trial, promise was anticipated for a low-FODMAP diet (limits foods high in fructose, lactose, fructans, galactans and polyols); however, study results were barely significant.

Does Fiber Make a Difference?

The relationship between fiber and IBS guessed it...not straightforward. First, let's explain that there are two types fiber - soluble and insoluble.

Soluble fiber attracts water and turns to a gel during digestion. It is found in foods such as oat bran, barley, nuts, seeds, beans, lentils, peas, some fruits and vegetables, and in psyllium, a common fiber supplement. Research has shown it to be beneficial in IBS, helping to soothe and regulate the digestive tract.

We'll review insoluble fiber in the next slide.

The Dilemma Associated With Insoluble Fiber

Insoluble fiber is found in foods such as wheat bran, vegetables, and whole grains. It is a powerful digestive stimulant and helps food to pass more quickly through the stomach and intestines.

Unfortunately, research has found it not so good for people with IBS. The dilemma is that insoluble fiber is found in a lot of healthy foods, so removing it from your diet all together is not a good idea, as you would be missing out on a valuable dietary component.

Eating small amounts of insoluble fiber and mixing foods that contain both soluble and insoluble fiber seems to help.

Probiotics Can Reduce Bloating and Gas

Probiotics are "friendly" bacteria that naturally live inside our bodies. Many experts believe a lot of our digestive problems arise when the balance of bacteria inside our gut gets out of balance. Supplements that contain a mixture of Lactobacillus and Bifidobacterium seem to work best for IBS.

Prebiotics are nondigestable food ingredients (usually a type of carbohydrate) that act like food for bacteria. Sometimes you will find a prebiotic mixed with a probiotic (called a synbiotic). Evidence so far hasn't found these as good for IBS, but research is ongoing.

Relieving Those Cramps

Most of the pain experienced in IBS is caused by spasms that occur in the walls of your intestine. Antispasmodics such as hyoscyamine (Anaspaz, Cystospaz, Levsin) and dicyclomine (Bentyl) relieve colicky-type pain and are good for occasional use. However, they do tend to cause side effects such as a dry mouth, drowsiness, and constipation.

Try peppermint oil capsules as an alternative to antispasmodics. It has a similar effect but without any side effects.

Stop the Sprints and Use of Antidepressants

Loperamide (Diamode, Imodium) stops those fast sprints to the toilet, but be careful not to overdo the dosage or you end up going from one extreme (diarrhea) to the other (constipation).

Antidepressants such as amitriptyline, doxepin, escitalopram (Lexapro), citalopram (Celexa) are effective at relieving abdominal pain and providing overall symptom relief in people with IBS. However, side effects such as weight gain, drowsiness, constipation, and sexual dysfunction tend to limit their use for IBS.

Viberzi For IBS With Diarrhea (IBS-D)

Eluxadoline (Virbezi) treats abdominal pain and diarrhea, hallmark symptoms of IBS-D. It is the first in its class and provides a welcome treatment alternative to standard anti-diarrheal medicines.

Virbezi works on opioid receptors to relieve diarrhea and is classified as a controlled substance. Potentially it is a target for people who abuse prescription medicines or street drugs. Theoretically, there is a risk of psychological dependence.

Common side effects of Virbezi include constipation (although severe constipation is rare), nausea and abdominal pain. Pancreatitis is more likely to occur in people who drink more than three alcoholic drinks per day. People aged over 65 years may be more likely to develop side effects but anybody who develops severe, unusual abdominal pain or constipation that lasts longer than four days should call their doctor. Sphincter of Oddi spasm - a contraction of the muscular valve that controls the flow of bile and pancreatic juice - is rare but people without a gall bladder are more at risk.

Trulance For IBS With Constipation (IBS-C)

Trulance (plecanatide) was approved in January, 2018 for the treatment of adults with IBS-C.

Trulance is structurally similar to uroguanylin, which is a substance released naturally by the walls of our intestine. Just like uroguanylin, Trulance results in an increase in the secretion of chloride and bicarbonate into the intestine, a decrease in the reabsorption of sodium, and an influx of water into the intestines. Some experts believe an upset in the fluid balance within the gastrointestinal tract contributes to chronic IBS.

The combined influx of water and higher concentration of sodium helps to soften and loosen stools and increase bowel movements. In addition activation of certain receptors (called GC-C-receptors) by Trulance may help decrease pain and inflammation within the intestines. Trulance exerts its effects mainly in the small bowel.

Trials have shown that Trulance significantly reduces abdominal pain and improves stool frequency and consistency. It reduces straining with bowel movements, with 4% of people reporting diarrhea as a side effect.

Other IBS Agents

Both Linzess and Amitiza soften stools and stimulate bowel movements, so they are effective in people with constipation-predominant IBS (IBS-C), but not so good for people who have diarrhea as their main symptom.

In April 2019, the FDA approved the reintroduction of Zelnorm (tegaserod) for IBS-C in women under the age of 65. Zelnorm was voluntarily withdrawn from the market in 2007 due to safety concerns, but a review of the literature in addition to its proven effectiveness at treating some of the most bothersome IBS-C symptoms saw it again get the tick of approval from the FDA.

Ibsrela (tenapanor) is another option for adults with IBS-C. It acts directly on the sodium-hydrogen exchanger NHE3 in the gastrointestinal tract, improving the movement of fluid into the bowel, increasing bowel movements, and decreasing abdominal pain associated with IBS-C.

Rifaximin (Xifaxan) is an antibiotic used occasionally in diarrhea-predominant IBS to relieve bloating and reduce overall symptoms.

Alosteron (Lotronex) has some rare, but serious, side effects and can only be prescribed for women suffering with severe, disabling, diarrhea-predominant IBS.

Improving Symptoms: Start With Your Diet

Keeping a food diary may help you to work out what foods seem to trigger your IBS. Be prepared to experiment with many different foods, as this is often harder to work out than it seems. Also be aware that even if you eliminate certain foods, you may still get IBS symptoms.

Many people with IBS find gluten-free diets helpful, and avoiding foods like cabbage, beans and cauliflower may cut down on the amount of gas produced. Restricted diets are notorious for lacking in certain vital nutrients so talk with a dietician to make sure you are still getting what you need each day.

What Else Can I Do To Help My IBS?

Eating small, regular meals throughout the day is kinder on your digestive system than skipping meals or having massive feeds.

Water is the best liquid you can drink. Alcohol and beverages that contain caffeine stimulate your intestines and can make diarrhea worse. Carbonated drinks just give you more gas!

Exercise is a great mood lifter and can help reduce any anxiety you may have about your condition.

A heating pad to place on your stomach when the pain is bad may also help.

Nerva is an online program that uses evidence-based hypnotherapy techniques to help you learn automatic skills to help fix the miscommunication between your gut and brain. The program was designed by Dr Simone Peters, who ran a clinical trial with Monash University that found her approach worked just as well as the Low FODMAP diet in helping you live well with IBS.

Build Your Support Network

There are going to be times when you don't feel like doing things. Having friends and family that understand your condition is important.

It's far easier to say "I'm feeling really unwell, I can't come out tonight", than to make up excuses for backing out of plans.

If you have chosen your friends wisely, they'll want the best for you. Sharing how you feel with somebody that cares provides a good outlet for your emotions as well.

Finished: Bowled Over By Your Bowel: IBS Causes, Risk Factors and Treatments

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