Table of Contents
What is Irritable Bowel Syndrome?
Irritable bowel syndrome (IBS) is a long-term or chronic condition that affects the large intestine. In the United States, IBS affects between 25 and 45 million people. IBS can affect people of any age but it is more common in younger people and the majority of patients are under the age of 50. Irritable bowel syndrome is twice as common in women than in men. 
IBS is not a single disease but is a collection of symptoms. The most common symptoms of IBS include abdominal pain, frequent or urgent bowel movements, constipation, and diarrhea. Sufferers may also have additional symptoms on top of these.
Doctors do not currently know the exact cause of irritable bowel syndrome. Keep reading to learn how IBS is diagnosed and medications for treatment like Xifaxan.
There is no one physical test to determine whether or not a patient has irritable bowel syndrome. IBS has similar symptoms to other conditions such as diverticulitis, colitis, and appendicitis. IBS symptoms may also change over time, making a patient feel like they had different conditions during the period. If a patient has symptoms such as abdominal pain, constipation, and diarrhea, then doctors may begin by ruling out other conditions.
In order to rule out other conditions, doctors may complete a medical history of the patient and try to find a pattern to the symptoms. Doctors’ questions may involve asking about symptoms, recent infections, diet, and other medical conditions. Symptoms such as rectal bleeding, bloody stools or weight loss are not signs of IBS. These may indicate a different intestinal or bowel condition.
Doctors may also perform imaging or laboratory tests. Imaging tests are a way to allow doctors to see an internal image of the body. Doctors could also order laboratory tests or imaging tests such as x-rays, colonoscopies, or CR scans to rule out other conditions. Laboratory tests can include stool tests, endoscopies, and lactose intolerance tests.  
Once doctors have performed initial tests to rule out other conditions, they may then diagnose IBS. As previously mentioned, there is no specific test to diagnose irritable bowel syndrome. Instead, doctors will decide whether or not a patient meets the given criteria.
b. The Rome IV Criteria
Today, irritable bowel syndrome is typically diagnosed using the Rome IV criteria. As the name suggests, this criterion has been updated multiple times after the initial Rome criteria was first created in 1990.
The primary symptom of IBS is abdominal pain. In order to be diagnosed as having IBS under the Rome IV criteria, patients must have abdominal pain plus at least two of the following symptoms:
- The abdominal pain is related to defecation and is partially or completely relieved after a bowel movement.
- Changes in the frequency of stools.
- Changes in the appearance of stools.
In order to be diagnosed with IBS, patients should have experienced these symptoms at least once a week for at least three months, and symptoms should have started at least six months previously. However, if you have recurrent symptoms, it can be beneficial to see a doctor before six months so that treatment for symptoms can begin. 
Although these are the symptoms used to officially diagnose irritable bowel syndrome, other supporting symptoms are also named. Other symptoms of IBS include changes to the urgency of stools, abdominal bloating, and the appearance of mucus in the stools. 
c. Different types of IBS
Once irritable bowel syndrome has been diagnosed, it may be categorized into one of three groups, depending on the patient’s symptoms. The letter after IBS signifies whether patients have diarrhea or constipation.
- IBS-D: Abdominal pain and diarrhea.
- IBS-C: Abdominal pain and constipation.
- IBS-M: (IBS Mixed) Abdominal pain and a mix of diarrhea and constipation.
IBS-M is also known as IBS-A for alternating as patients can alternate between the two symptoms. Research shows that patients who have IBS-M are more likely to have more pain than patients with IBS-D or IBS-C. Doctors do not know the cause of irritable bowel syndrome, and it is also unknown what causes the differences between IBS-D, IBS-C and IBS-M. 
d. IBS Treatments
To treat IBS, doctors may prescribe different medications to relieve specific symptoms. However, prescription medications are not a long-term solution to irritable bowel syndrome. These medications only relieve specific symptoms rather than treating the cause of the condition.
Doctors may prescribe different medications depending on whether a patient has IBS-C, IBS-D, or IBS-M. For patients who have IBS-D, Xifaxan is often prescribed. Xifaxan is the brand name of rifaximin and is an antibiotic that fights infections in the intestines to lessen diarrhea. 
When patients are suffering from constipation and abdominal pain (IBS-C), doctors may prescribe Linzess. Linzess is the brand name for linaclotide, which stimulates bowel movements by increasing the release of chloride and water into the intestines. 
As well as using prescription medications, making lifestyle and diet changes can also ease the symptoms of IBS. Doctors and dieticians can help create a suitable diet based on patients’ symptoms.
The content in this article is intended for informational purposes only. This website does not provide medical advice. In all circumstances, you should always seek the advice of your physician and/or other qualified health professionals(s) for drug, medical condition, or treatment advice. The content provided on this website is not a substitute for professional medical advice, diagnosis or treatment.