- You may have irritable bowel syndrome (
IBS ) if you have symptoms like abdominal pain, bloating and gas, cramping, diarrhea, or constipation. - A doctor can evaluate your symptoms and do lab tests on your blood and stool to confirm the diagnosis.
- IBS is usually caused by a gut infection, bacterial overgrowth in your gut, or a mental
health condition like anxiety or depression. - This article was medically reviewed by Rudolph Bedford, MD, a gastroenterologist at Providence Saint John's Health Center in Santa Monica, California.
Irritable bowel syndrome, or IBS, is a condition that affects the large intestine and can cause abdominal discomfort, constipation, and diarrhea. An estimated 10-15% of adults have the condition, making it one of the most common gastrointestinal diseases in the US. Here's what you need to know about IBS and how it's treated.
What is IBS?
IBS is a gastrointestinal disorder that mainly affects your large intestine, also known as the colon. While other GI conditions may cause visible damage to the intestines, IBS does not. It's considered a brain-gut disorder, in which the brain and gut are not working together optimally, which can result in increased gut sensitivity.
Although the condition is not life-threatening, it can be long-lasting, and the symptoms can affect your quality of life if they aren't managed.
There are three main subsets of IBS, based off of your primary symptoms:
- IBS-D/IBS with diarrhea: Diarrhea and loose stools are more predominant than constipation.
- IBS-C/IBS with constipation: Constipation is more predominant than diarrhea.
- IBS-M/IBS mixed: You experience a mix of both constipation and diarrhea and the two can alternate often.
Symptoms of IBS
IBS results in a variety of gastrointestinal symptoms. According to James Buxbaum, MD, a gastroenterologist at Keck Medicine of USC, symptoms of IBS include:
- Abdominal pain
- Bloating and gas
- Cramping
- Diarrhea
- Constipation
While most people experience one or more of these symptoms from time to time, it doesn't mean they have IBS.
"While symptoms such as constipation and diarrhea are nearly universal approximately, [only] 10-20% have a persistence and severity of symptoms to fulfill the diagnosis of irritable bowel syndrome," says Buxbaum.
He says a diagnosis of IBS requires both:
- Three months of symptoms of abdominal discomfort
- A change in stool frequency or form in the previous six months
Diagnosis of IBS
IBS is usually diagnosed by the doctor taking your history, asking about your symptoms, and performing some tests. Much of the testing will be to rule out something more serious such as IBD (inflammatory bowel disease).
The doctor will ask about your symptoms, severity and frequency of symptoms, as well as some more specific questions. For example, Buxbaum says a sign can be if they are only having these symptoms and bowel movements during the day, which is more typical of IBS than IBD, where someone might be waking up in the middle of the night and having diarrhea. Some other signs that it's IBD rather than IBS are:
- Fever
- Weight loss
- Blood in the stool
Your doctor can also do some lab tests on blood and stool to check for inflammatory markers. If these tests come back normal, Buxbaum says this is encouraging that a patient is experiencing IBS and not IBD. Additionally, in tricky cases and depending on age, a colonoscopy may be performed.
Diagnosis of IBS requires three months of symptoms of abdominal discomfort with a change in stool frequency or form beginning in the previous six months."
Causes of IBS
Experts aren't sure what causes IBS, but there are some factors that can increase a person's risk including:
- Gut infection. Contracting an infection in your gut like E. Coli, for example, Buxbaum says, because the gut immune system is dysregulated. IBS will appear soon after.
- Bacterial overgrowth such as SIBO (small intestine bacterial overgrowth) can cause IBS. "SIBO likely causes dysregulation of the intestinal immune system. Additionally, the gas production related to these bacteria may be perceived as intense bloating for those with visceral hypersensitivity [increased sensitivity to pain in the organs]," says Buxbaum. Visceral
- Mental health condition such as anxiety, depression, or history of trauma. Buxbaum says these conditions are associated with visceral hypersensitivity, which is why people with these conditions may be more likely to develop IBS. Visceral hypersensitivity is believed to play a large role in IBS.
- Genetic predisposition. If your family has a history of IBS you're more likely get it.
Treatment of IBS
After your doctor has ruled out other GI conditions, such as IBD, you can start your path to relief from IBS. There are various treatments available to help people with IBS live more comfortably by reducing flare-ups and symptoms. Here are different treatments, both prescription, over-the-counter.
Prescription medications:
- Antispasmodics: An antispasmodic is an anti-spasm medication that can relax the muscles of the digestive tract and relieve the cramping that IBS causes. Buxbaum says two of the most popularly prescribed antispasmodics for IBS are Bentyl and Levsin.
- Constipation medications: There are some meds that can help get more fluid in your gut, Buxbaum says, which can help relieve constipation for those with IBS-C. Amitiza and Linzess are two popular prescription choices in this category.
- Diarrhea medications: If your diarrhea is uncontrollable, there are drugs that can slow down the movement of waste through your colon and also reduce contractions in the intestines. Buxbaum says two prescription choices here are Viberzi and Lotronex (which is primarily for women with severe IBS). Over the counter anti-diarrheal medicines such as Imodium can be used intermittently, Buxbaum says.
- Antidepressants: In IBS cases where there is an anxiety component, and stress is a major trigger for episodes, antidepressants may be prescribed, according to Buxbaum. Antidepressants aren't just for depression – they are commonly used to treat anxiety. Getting anxiety under control can be key in getting IBS symptoms under control.
Diet and lifestyle changes
Many people can help control their symptoms through a change in diet.
- Adding fiber to your diet: According to Buxbaum, increased fiber intake is especially important for people who have mostly constipation, or IBS-C. He says fiber can bulk up your stools and improve how regularly you have bowel movements. If you're having trouble adding fiber into your diet, you can try a fiber supplement such as Metamucil.
- Avoiding foods that can trigger IBS symptoms: Diet plays a huge role in IBS, and avoiding foods and drinks known to trigger gas and bloating as well as foods that can cause diarrhea or constipation. Buxbaum says patients may want to avoid or limit the following:
- Dairy products that include lactose
- Certain fruits like apples, mangos, pears, and peaches
- Certain vegetables such as brussels sprouts, broccoli, asparagus, and cauliflower
- Foods high in Galactooligosaccharides (GOS) such as soy products and legumes
- Artificial sweeteners
- Alcohol
- Caffeine
- Carbonated drinks
- High FODMAP foods, such as dairy, fruits, and wheat
Also, remember the basics of staying healthy. Sometimes we get so wrapped up in everything that we forget the basics. Get enough sleep, staying hydrated, and managing stress levels can go a long way.
On top of all these tips, Buxbaum says it's important to have a doctor you trust and who is a good listener, since you want to be able to have a good long-term relationship and therapeutic alliance with your gastroenterologist to manage your symptoms in the long run.