What is IBS?

Most of us are familiar with the discomfort of an upset stomach. For people with irritable bowel syndrome (IBS), however, this discomfort involves more than just a stomachache. IBS is a chronic condition that mostly affects people under the age of 50. It does not cause cancer or hurt the gastrointestinal tract, but it can interfere with work, school, social events and daily life.

If you think you may have IBS, this article will cover different types of symptoms, who may be more prone to the condition, and common treatment methods.

In this article:

Understanding Irritable Bowel Syndrome

People with IBS experience abdominal pain and altered  bowel movements. These stool changes are what determines a person's IBS subtype. Because different types of IBS have different symptoms, knowing which category your symptoms fall into can help your health care provider determine the best course of treatment.

Types of IBS

There are four types of IBS: IBS-C, IBS-D, IBS-M and IBS-U. Patients are diagnosed with constipation-predominant IBS (IBS-C) if the stool is hard and lumpy more than 25% of the time and mushy or watery less than 25% of the time. Patients with diarrhea-predominant IBS (IBS-D) pass mushy or watery stool more than one-quarter of the time and hard, lumpy stool less than 25% of the time.

However, IBS symptoms don’t always fit into one category or the other. A person may have mixed bowel habits, IBS (IBS-M) if they alternate between constipation and diarrhea. The fourth category is unclassified IBS (IBS-U). These patients experience other symptoms of IBS, but stool changes don't occur as often.

How common is IBS?

IBS is a common condition. Approximately 10% to 15% of the United States population has IBS. The majority of people develop IBS in early adulthood, prior to age 35. Women have been shown to be twice as prone to the disorder than men. IBS is also thought to affect approximately 5% of children between ages 4 and 18.

Symptoms of IBS

According to board-certified Internal Medicine Physician Dr. Brennan Kruszewski, “Common symptoms of IBS include abdominal pain, cramping, diarrhea, and constipation. Symptoms of IBS may mimic those of other digestive diseases, like inflammatory bowel disease, celiac disease, or even bowel cancers. Because of this, it's important to seek the advice of a physician if you are experiencing a change in bowel habits.”

With IBS, symptoms are present for at least 3 months with a varying degree of severity. Symptoms can range in severity, and some are more common than others.

Here are the various ways in which IBS can manifest.

Common symptoms

The main symptom of IBS is abdominal pain accompanied by a change in bowel habits. This can take the form of constipation, diarrhea or a combination of the two. While every person’s experience with the condition is different, some research suggests people diagnosed with IBS-C may experience more bothersome stomach pain more frequently than individuals with IBS-D or IBS-M. Patients with IBS-C may also be more likely to experience spreading abdominal pain than those with IBS-D. It is also not uncommon to experience abdominal cramping, gas, distension or bloating. People who menstruate and are diagnosed with IBS may find this group of symptoms increases during menstruation.

Less common symptoms

While not as common, another potential sign of IBS includes a sudden urge to use the bathroom. This is known as fecal urgency and has been linked with constipation, diarrhea and IBS-D. Some people may also experience incomplete bowel movements or the feeling that there is still more stool to pass. Another symptom of IBS is mucus in one's stool.

Causes and risk factors of IBS

The exact cause of IBS is still unknown, but a number of factors may influence why some people are more prone to the condition than others. Physiological factors, genetics, mental health, and food triggers are all thought to potentially play a role.

Physical causes

The brain and the gastrointestinal tract talk back and forth to one another. This two-way communication is referred to as the gut-brain axis. When this communication loop is interfered with, experts believe it may prompt symptoms of IBS. Our digestive tract is also home to a diverse collection of bacteria called the gut microbiome. Disruptions in the balance of bacteria may be another potential cause of IBS. Some research suggests that the makeup of gut bacteria in patients with IBS may be different from the gut microbiota of people without the condition.

Gut motility, meaning the movements of the digestive system, may also be a contributing factor. One study showed food moved more slowly through the gastrointestinal tract of people with IBS-C. Another theory is that certain pathogens, including bacterial, viral and protozoal, may cause post-infection irritable bowel syndrome (PI-IBS). Some examples of pathogens are E. coli, salmonella, and norovirus, which are commonly referred to as "stomach bugs.”

Psychological causes

Some mental health disorders have also been associated with IBS. Anxiety and depression have been shown to affect as many as one-third of patients. Experts suggest this may be due to impairment of the hypothalamic–pituitary–adrenal (HPA) axis. This system helps protect the body against the harmful effects of stress. Stress may also impact intestinal functioning. When stressed, the body responds by releasing a neuropeptide called corticotropin-releasing factor, which may mess with the gastrointestinal tract​.

Symptom Triggers

Diet may influence symptoms of IBS, particularly for people with food intolerances or sensitivities. Abdominal discomfort may set in a few hours after eating or within 15 minutes. Some individuals with IBS may have increased symptoms related to ingestion of wheat and gluten.

Food triggers are more common among people with IBS-D. Triggers can differ from individual to individual, but some common examples of irritating foods include fruits, vegetables, dairy products, legumes, and chocolate. Fatty foods may be bothersome for individuals who predominantly experience gas or diarrhea. Certain beverages are also common triggers for symptoms. This includes alcohol, which can harm the lining of the intestines and prompt changes in gut motility. Patients who drink coffee may find that they experience stomach pain and loose bowel movements, as caffeine can ramp up stomach acid production and colon contractions.

Risk factors

Some people may naturally be more vulnerable to IBS, particularly if the condition runs in the family. Research shows a person’s risk of IBS nearly doubles or triples if they’re related to someone with the condition. Women are also shown to be up to twice as likely to develop IBS than men. Being younger than 50 years old is also considered a risk factor. IBS symptoms become less common with age, with prevalence rates dropping by 25% among people over 50 years old. All the more reason to look forward to the big five-oh.

Diagnosis of IBS

Your doctor will evaluate your symptoms by taking a thorough medical history, conducting a physical exam and ordering additional tests as needed to help establish the diagnosis of IBS. They will also want to know about any family history of inflammatory bowel disease, colon cancer or other gastrointestinal issues. Your physician will likely ask questions about diet, medication, any changes in bowel habits, and frequency and duration of symptoms. Because IBS can present similarly to other intestinal diseases, most doctors will also order additional testing. This may include a colonoscopy, blood work or stool test. Keeping a written log that tracks when gastrointestinal symptoms occur and potential triggers can help your health care provider confirm a diagnosis. Patients will want to share these notes with their doctor at their appointment.

Diagnostic tests

No specific test will be able to confirm whether a person has IBS, but they can help your health care provider narrow down the cause of symptoms. For example, a stool sample may be collected to rule out potential infection or inflammation. Blood tests may be used to look for anemia as well as other gastrointestinal disorders. This may include testing for celiac disease, which is often associated with IBS-D and IBS-M subtypes.

Alarm signs for other serious gastrointestinal disorders include:

• Age of onset after age 50 years
• Rectal bleeding or melena
• Nocturnal diarrhea
• Progressive abdominal pain
• Unexplained weight loss
• Laboratory abnormalities (iron deficiency anemia, elevated C-reactive protein or fecal calprotectin/lactoferrin)
• Family history of IBD or colorectal cancer

Additional evaluation to exclude other causes of similar symptoms may be needed in those individuals who present with alarm symptoms.

"In certain cases, your doctor might recommend additional imaging studies, like a CT scan, MRI, or pelvic ultrasound,” says board-certified Internal Medicine Physician Dr. Brennan Kruszewski. “While not everyone with IBS needs these tests, they can help differentiate IBS from other conditions.”

Colonoscopy

To get a closer look at what’s going on in a patient’s large bowel, your doctor may recommend a colonoscopy. A patient is typically placed under anesthesia during the procedure. A narrow tube with an attached camera (called a colonoscope) is then inserted into the anus. To give the camera an unobstructed view, the instrument releases air to inflate the large intestine. A colonoscopy can be used to investigate changes in bowel movements as well as symptoms of abdominal pain, bleeding and weight loss.

Treatment and management

IBS is not curable, but different treatment options can help manage symptoms. Medical treatment, mental health support, and lifestyle changes are all options that may be explored. Gaining a better understanding of what may be contributing to your symptoms can help you and your health care provider develop a personalized treatment plan. If your symptoms appear to be linked with food triggers, making certain dietary changes may be recommended. If stress is a contributing factor, implementing stress reduction techniques may be your primary focus.

Dietary modifications

Keeping a personal log of foods eaten, symptoms experienced, and any patterns that emerge can help with identifying potential food triggers. Some people may want to reduce their intake of these specific foods or eliminate them from their diet altogether. Always consult with your health care provider before making any significant dietary changes or eliminating any foods.

Activity management

Everyday life activities can also influence our digestive health, including exercise and sleep habits. Research has shown that increased physical activity may benefit patients with IBS-C, IBS-D and IBS-M. Relaxation techniques may also help mitigate the effects of stress on our gut. Calming activities, such as yoga, massage, or practicing mindfulness, may alleviate symptoms of IBS. Getting enough sleep may also reduce stress levels as well as digestive discomfort. While these practices may benefit people with mental health disorders too, professional treatment may be encouraged for people with IBS who also experience anxiety and depression.

Medications

Laxatives or fiber supplements may be recommended for patients with IBS-C. Patients with IBS-D may be recommended to take antidiarrheal medicines. Antibiotics may alternatively be prescribed if diarrhea symptoms are due to infection. Prescription drugs are also available for IBS-C and IBS-D. Certain antidepressants may be prescribed for patients experiencing both IBS and depression. Your health care provider will determine which medications are right for you. Always consult with and inform your health care provider of any over-the-counter medication you may be taking.

This content is for informational purposes only and is not medical advice. Consult your health care provider before taking any vitamins or supplements and prior to beginning or changing any health care practices.