Irritable bowel syndrome (IBS) is one of the most frequently diagnosed gastrointestinal (GI) disorders. It affects your lower gastrointestinal tract. This includes the small intestine and large intestine (colon).

It’s a chronic condition that most people can effectively manage through a combination of dietary adjustments, medication and behavioral therapy.

Scientists classify IBS by how your poop looks when you’re experiencing symptoms. People with IBS typically have normal bowel movements some days and abnormal ones on other days. The type of IBS you have is determined by the pattern of your abnormal bowel movements.

• IBS with constipation (IBS-C): Mostly hard poop with belly pain
• IBS with diarrhea (IBS-D): Mostly loose poop with belly pain
• IBS with mixed bowel habits (IBS-M): Alternating between hard and loose poop with belly pain

Know the Symptoms

Each person with IBS has a unique set of symptoms, and they can mimic symptoms of other diseases. There can also be periods where symptoms disappear completely. The most common symptom of IBS is abdominal pain or discomfort in your belly. Other symptoms include:

• Bloating and/or abdominal distention (swelling of the belly as determined by a physician)
• Increased gas production
• Increased intestinal gurgling, rumbling or other sounds
• Mucus-covered stool
• Diarrhea, constipation, or switching between the two
• Changes in bowel habits, including increased or decreased frequency and urgency, straining, and feelings of incomplete bowel movements
• Non-GI symptoms (and conditions), such as migraines, anxiety, brain fog, chronic fatigue, anxiety and depression

Is It IBS or IBD?

IBS is not the same as inflammatory bowel disease (IBD), which includes Crohn's disease and ulcerative colitis and is caused by inflammation. IBS is not caused by inflammation and does not damage bowel tissue or increase your chances of developing colorectal cancer. People may have symptoms of both IBS and IBD at the same time.

Get a Diagnosis

Between 10% and 15% of adults worldwide are affected by IBS, but the majority do not seek medical care, so they remain undiagnosed or unaware they have a real condition. “We estimate that approximately 75% of people in the United States with IBS have yet to be definitively or accurately diagnosed,” states Darren M. Brenner, MD, director of the Neurogastroenterology and Motility Program at the Digestive Health Center at Northwestern Memorial Hospital.

If you experience symptoms and think you might have IBS, do not try to self-diagnose — talk with your physician. This is the best way to find out the cause of your symptoms and start a treatment plan to improve your quality of life.

The effective management of IBS begins with an accurate diagnosis. Dr. Brenner explains that this involves using an established set of criteria called the ROME criteria. These criteria make sure patients have symptoms consistent with IBS. It is also important to rule out signs or symptoms that indicate another diagnosis.

Generally, eight questions can be used to determine whether a patient has IBS with a high level of accuracy:

• Do you have pain or discomfort?
• Is the pain made better or worse when you have a bowel movement?
• Is this pain associated with a change in the frequency or form of your stools?
• Are you older than 50?
• Is this pain a recent change?
• Do you have unexplained, unintentional weight loss?
• Are you anemic (low number of red blood cells) or have repeated GI bleeding?
• Do you have a family history of colon cancer, IBD or celiac disease?

“For many patients, these criteria allow us to make a definitive IBS diagnosis with an accuracy that approaches 97% to 98%,” says Dr. Brenner. "This is important because a quick and accurate diagnosis can minimize the amount of unnecessary diagnostic testing performed and allow for more efficient treatment. I cannot emphasize enough that IBS is not a diagnosis of exclusion, which is a diagnosis reached by a process of elimination."

Manage the Symptoms

If you are diagnosed with IBS, lifestyle changes can help manage symptoms and prevent flare-ups. “You should work together with your care team to identify whether different foods exacerbate your IBS symptoms,” says Dr. Brenner. "If you determine there are specific food triggers, your diet can be personalized to reduce these symptoms. Regular exercise has been shown to be beneficial as well.”

Although the frequency, duration and severity of IBS symptoms vary from person to person, the following factors can increase symptoms:

• Stress
• Lack of sleep
• Menstruation
• Food intolerances

“Some foods can trigger fluid shifts and gas production in the intestines of people with IBS,” explains Bethany M. Doerfler, RD, a dietitian at Northwestern Medine. “These foods are collectively known as high FODMAP, which is an acronym for fermentable oligosaccharides, disaccharides, monosaccharides and polyols.” Research shows that reducing high FODMAP foods can improve global IBS symptoms.

Common high FODMAP foods include:

• Excess Fructose: A simple sugar found in high fructose corn syrup and some fruits, such as watermelon, juices, asparagus, apples and cherries
• Lactose: A carbohydrate found in dairy products like milk, ice cream and some yogurts
• Fructans: Found in many foods, including grains like wheat, onions, garlic and barley
• Galactans: A complex sugar found in foods like beans and lentils, soy products and cruciferous vegetables like Brussels sprouts and cauliflower
• Polyols: Sugar alcohols that can be naturally occurring or artificially made to substitute sugar, such as sorbitol, xylitol and isomalt

“Working with a registered dietitian can help you navigate the complexities of a FODMAP diet and help you find healthy IBS-friendly foods,” says Doerfler.

If you have IBS, there is always a possibility of a flare-up. However, knowing how to manage your symptoms can empower you and give you back some degree of control.

In addition to lifestyle modifications, there are other treatment options that can help. These range from prescription medications to behavioral therapies like cognitive behavioral therapy and gut-directed hypnotherapy. The behavioral therapies have consistently been shown to be effective in reducing symptoms for at least 70% of IBS patients.

If you have digestive issues, talk with your physician — even if you've already been diagnosed with IBS. In the event something has changed, your treatment plan may change as well.