The gastrointestinal tract is the passage through which food travels in and out of the body. Irritable bowel syndrome (IBS) occurs when events in the lower GI tract (small intestine and colon) cause diarrhea, constipation, bloating, and/or cramping.
The largely accepted criteria for diagnosing IBS (Rome IV) is that the patient has recurrent abdominal pain that alters bowel habits at least one day a week, on average, for three months. The changes in bowel habits related to the abdominal pain should include at least two of the following:
- Bowel movements that either increase or relieve pain.
- A change in stool frequency.
- A change in stool form and appearance.
It is believed IBS results from a misfire in how the brain and gut interact, causing food to move too fast or too slowly. In general, the condition is a group of disorders characterized by a combination of: the way food moves through the GI tract, the gut’s hypersensitivity to pain, changes in the bacteria in the gut, changes in the gut’s immune defenses, and changes in how the central nervous system receives and sends information to the gut. For some people, even a normal amount of food or gas could cause pain.
IBS does not put its patients at higher risk of more serious GI conditions, such as inflammatory bowel disease or colon cancer. However, it can compromise the patient’s quality of life and cause stress related to the uncertainty of when an urgent bowel movement will strike.
The condition is estimated to affect 10% to 15% of the U.S. population; however, many people with symptoms do not see a doctor.
In addition to meeting the Rome IV criteria for IBS above, other symptoms may include:
- An urgent need to go to the bathroom
- Bloating and gas
- A whitish mucus in the stool
IBS is best identified through an exam of the belly and review of the patient’s medical history. It would be helpful for the patient to keep a journal of the foods eaten and IBS symptoms.
Your gastroenterologist may also call for the following tests:
- Blood exam – A blood sample would be tested for conditions outside of IBS, such as anemia, infections, and celiac
- Stool exam – A sample would be analyzed for blood, infections, and diseases.
Based on the results of these tests, your doctor may order a screening:
- Upper endoscopy – The gastroenterologist inserts a camera-equipped flexible tube into the esophagus through to the small intestine to examine and biopsy the tract for celiac disease or other causes.
- Colonoscopy – This procedure involves the insertion of the tube through the anus, to examine the entire colon. If polyps are present, they will be removed during the procedure.
- Breath test – A sample of the breath is examined to detect if the patient is lactose intolerant, or intolerant to dairy.
Symptoms of IBS vary by patient and treatment plans are tailored to the unique combination of symptoms. Typically, these treatments include one or more of the following:
- Diet – While diet does not cause IBS, some high-fat foods, dairy, and gluten could worsen symptoms. With a food journal, the patient and doctor can narrow down culprits. Some people are finding relief in a low-FODMAP diet, which refers to a group of sugars in some foods: lactose, fructose, fructans, galactans (found in legumes), and polyols (naturally occurring sugar alcohols).
- Medications – Over-the-counter drugs or probiotics may be prescribed to relieve diarrhea or constipation symptoms. Antidepressants may be ordered to reduce pain.
- Mental health therapies – Behavioral and psychological treatments include stress management, gut-specific hypnosis, biofeedback, relaxation, and pain management techniques.