IBS symptoms can include: (3,4)

• Abdominal pain
• Cramping or bloating
• Excess gas
• Diarrhea or constipation, or alternating bouts of each

But not all IBS is the same. There are four types: (4)

1. IBS-D may involve loose stool, an urgent need to go to the toilet, cramps, and stomach pain.
2. IBS-C may cause an inability to move the bowels or an urge to go but you can’t.
3. IBS-mixed includes both diarrhea and constipation symptoms.
4. IBS-unspecified symptoms follow an irregular pattern.

Researchers don’t know exactly why some people get IBS, but they speculate that stress, certain foods, and nerve signals between the gut and brain may trigger symptoms. (5)

The Brain and Gut Connection

Millions of nerve cells reside in the lining of the GI tract, almost like a second brain. It is called the enteric nervous system, and it controls digestion and tells the bowels when to contract, move, and secrete fluids. There’s emerging evidence that the brain and gut communicate through this major network of nerves. (6)

Some experts think that IBS is caused when there’s a glitch in that communication. “We all respond to stress physically, and some of us physically react with our gut, as with diarrhea or constipation, while others get headaches or back pain,” Dr. Scheman says.

The problem is that the stress response in the gut can create a vicious cycle, in which the stress causes symptoms and vice versa, also known as a feedback loop. “Each time you go around it gets worse, like a downward spiral,” she says.

An Imbalance of Bacteria in the Gut

Conditions like bacterial gastroenteritis, also called the stomach flu, seem to alter the bacterial balance in the gut. In a review published in the journal Alimentary Pharmacology and Therapeutics, researchers found that the chances of developing IBS increased sixfold after an episode of gastroenteritis. Although experts aren’t sure how this change occurs, some speculate that damage to the nerves in the gut causes IBS symptoms to develop.

Other studies show that some people with IBS could also have small intestinal bacterial overgrowth (SIBO), a condition in which a large quantity of bacteria moves up to the small intestine and causes bloating, stomach pain, and excessive gas. A review published in March 2017 in the journal Gut and Liver found that 4 to 78 percent of people with IBS also had SIBO.

The relationship between the two conditions remains unclear, but the use of antibiotics has proved effective in reducing symptoms. (8)

Risk Factors for IBS

IBS can hit at any age, but people younger than 50 are more likely to develop it. The chances of getting it increase if you have a family member with IBS, a history of stressful life events, or a severe abdominal infection. (4)

Women are twice as likely to develop it than men. The reason why women are more affected than men is still up for debate, but some research, such as a study published in June 2014 in the World Journal of Gastroenterology suggests that hormones, particularly estrogen and progesterone, which fluctuate during the menstrual cycle, also reside in the digestive tract and can contribute to IBS flare-ups. (9)

There’s also evidence that people with IBS tend to suffer from mood disorders such as depression or anxiety. “There is a high overlap between the two,” says Jeffrey Baumgardner, MD, a gastroenterologist in Santa Rosa, California. “A significant number of people with IBS also have a history of some kind of abuse — emotional, physical, or sexual.”

Potential Triggers of Irritable Bowel Syndrome

Just as IBS varies from person to person, triggers of IBS symptoms can also be due to a number of factors, including:

• Certain foods or food ingredients such as dairy products, certain fruits, cruciferous vegetables like Brussels sprouts and broccoli, caffeine, and artificial sweeteners.
• Stress: While not a direct cause of symptoms, research suggests it may aggravate symptoms, causing them to be more severe and frequent.
• Hormones: Studies show estrogen may influence certain functions related to the digestive tract such as bowel movements and how the immune system functions in the gut.

While it may take some trial and error to figure out what’s causing symptoms, there are ways to manage them.

Although there is no standard test to diagnose IBS, your doctor will likely perform tests such as a colonoscopy, abdominal CT scan, or MRI to rule out serious conditions such as diverticulitis, IBD, and colon cancer. (10)

Once other conditions are ruled out, doctors sometimes use the guidelines known as the Rome criteria, which are a set of symptoms that help doctors give an accurate IBS diagnosis.

According to the latest revision, the Rome IV, symptoms such as abdominal pain should occur, on average, at least one day per week within the previous three months, accompanied by at least two of the following other symptoms: (11)

• Abdominal pain related to a bowel movement
• Changes in the frequency of bowel movements
• Changes in the appearance of the stool

IBS is a chronic condition that requires long-term management. (12) But finding the right treatment and lifestyle modifications (see below), can help keep symptoms under control.

There’s no one-size-fits-all treatment for IBS. Most IBS sufferers try different treatments before they find one or a combination of some that work. One way to start is by developing a sense of how your IBS interacts with your diet, mood, and stress level, as well as other areas in your life.

Your doctor will likely recommend the following strategies:

• Dietary changes
• Medications
• Psychotherapy (talk therapy)
• Alternative remedies such as acupuncture, probiotics, and meditative techniques

Depending on your symptoms, any combination of these options may be part of your treatment strategy.

Medication Options

Depending on your symptoms, your doctor may recommend fiber supplements or laxatives for constipation.

For diarrhea, loperamide (Imodium) is an over-the-counter option. Prescription anti-diarrheal medications include bile acid binders, such as cholestyramine (Prevalite), colestipol (Colestid), or colesevelam (Welchol).

Medications that can relieve bowel spams, such as dicyclomine (Bentyl), are sometimes prescribed to help with diarrhea, though they can cause side effects such as constipation, dry mouth, and blurred vision.

Pregabalin (Lyrica) or gabapentin (Neurontin) are pain medications that may help ease symptoms.

Antidepressants may also be prescribed, particularly if you have depression and abdominal pain.

A few medications have been specifically approved for certain people with IBS. (13)

For diarrhea:

• Eluxadoline (Viberzi), which reduces muscle contractions and fluid in the intestine, and improves muscle tone in the rectum.
• Rifaximin (Xifaxan), an antibiotic that can decrease bacterial overgrowth.

For constipation:

• Lubiprostone (Amitiza) and linaclotide (Linzess) work to increase fluid secretion in your small intestine to help you pass stool.

Alternative and Complementary Therapies

Emerging evidence suggests that acupuncture, yoga, and mindfulness meditation — which help reduce stress — can be helpful in easing IBS symptoms. (14)

Gut-directed hypnotherapy — which aims to alter your body’s responses to IBS symptoms by making the gut less reactive to emotional upheaval and stress and changing how the brain interprets signals from the gut — has shown promising results in research.

Modifying Your Diet

For people with IBS, figuring out which foods tend to cause symptoms can be tricky. Keeping a record of what you eat may help you figure out which foods you should avoid.

A low-FODMAP diet involves eating fewer foods containing lactose (found in dairy); fruits such as apples, pears, and cherries; cruciferous vegetables like broccoli and cauliflower; beans; and sugar-free gums and mints.

You may need to work with a doctor, dietitian, or nutritionist to narrow down what’s causing your symptoms.

Supplements such as peppermint oil and probiotics have been shown to have beneficial effects in reducing symptoms. (14)

Prevention of Irritable Bowel Syndrome

You can’t prevent IBS, but certain lifestyle modifications can help reduce the frequency and severity of symptoms. Dietary changes are often key when it comes to stopping IBS symptoms before they start. Depending on the type of IBS you have, you might want to avoid foods that produce gas (carbonated beverages, raw fruit, cruciferous vegetables), foods containing gluten, and FODMAPs. (13)

Learning to handle stress better may also aid in IBS prevention. Psychotherapy, mindfulness meditation, and yoga are stress-relieving techniques and activities that may help.

The chronic constipation or diarrhea of IBS can lead to hemorrhoids. (12)

Consider some of these suggestions:

• Talk with your partner about your anxieties.
• Learn stress-management techniques to help you relax.
• Avoid any trigger foods on the days you plan on getting intimate.
• Take medications to help relieve pain, gas, and diarrhea so you have one less thing to worry about.

Studies suggest that about 12 percent of Americans have IBS. (2) Women are about twice as likely to have IBS as men, but the frequency of IBS seems to be the same across race and ethnicity.

For years, experts thought that mood disorders such as anxiety and depression contributed to worsening IBS systems. But recent research into the brain-gut connection (mentioned above) suggests the association also goes the other way — that an irritated gut may send messages to the central nervous system resulting in mood changes. (6)

Stress — the body’s response to physical and emotional change, pressure, and challenges — is another condition connected to IBS. Stress activates certain neurotransmitters in the brain, which stimulate pain signals in the gut, worsening IBS.

Research suggests that the chronic pain disorder fibromyalgia may also be connected to IBS.

A condition that may be confused with IBS is irritable bowel disease (IBD), but they are completely different disorders. For one thing, IBS is more common than IBD, affecting about 12 percent of Americans, while IBD affects about 1.3 percent. (16)

IBD, usually categorized as either Crohn’s disease or ulcerative colitis, is linked to an abnormal reaction by the body’s immune system. The lining of the intestines becomes inflamed and ulcerated, which causes permanent damage to the digestive tract over time. These conditions often require medication and may even lead to hospitalization and surgery.

About IBS, from the International Foundation for Functional Gastrointestinal Disorders (IFFGD)

The IFFGD, a nonprofit organization, works with patients, families, healthcare providers, and researchers to increase awareness and understanding of gastrointestinal issues and to improve digestive health. Their page on Living with IBS delves into the challenges that people with IBS may face, from traveling to navigating holidays to being pregnant.

IBS Patient Support Group

This online community is great for IBS patients looking for support and connection. Community forums directly address a range of IBS issues, and you can also find resources on living with IBS, including patient diaries, and a podcast that includes conversations with patients, researchers, GI doctors, and dietitians.

Mayo Clinic

For clear, accurate health information, the Mayo Clinic is one of Everyday Health’s trusted go-to sources. Their comprehensive coverage of IBS goes beyond the basics, with tips on how to prepare for an appointment to discuss IBS with a gastroenterologist and what questions to ask.

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

In addition to in-depth review of symptoms, treatment, and how to manage IBS, the NIDDK’s site also offers the latest on clinical trials potentially available to IBS patients.