Types of IBS: Are you a C, D, M or U?

What is IBS?

IBS is a chronic (which means long-term) gastrointestinal disorder. It’s a common condition affecting approximately 10% of people worldwide.

The most common symptoms of IBS include:

• Abdominal pain
• Cramps
• Bloating and gas
• Mucous in stools
• Abnormal bowel movements: constipation (IBS-C), diarrhea (IBS-D), or mixed changes to bowel habits (IBS-M).

IBS  is a ‘syndrome’, which means a group of symptoms that commonly occur together. It is also a functional disorder, because symptoms may happen without a clear cause. It’s thought that some symptoms happen due to changes in the connection between the brain and the gut.

IBS subtypes

There are four main subtypes of IBS: IBS-C, IBS-D, IBS-M,and IBS-U. Each is named in relation to experience in bowel movements. There is some evidence that some people with IBS will alternate between them over time.

There also are two additional IBS subtypes that occur following diseases of the digestive tract (post-infectious IBS and post-diverticulitis IBS). Let’s have a look at each.

IBS with constipation (IBS-C)

IBS with constipation is a common type of IBS. In this type of IBS, you will experience fewer bowel movements overall and may strain when passing a stool.

For your IBS to be diagnosed as IBS-C, at least 25% of your stools are hard and lumpy, and fewer than 25% are loose in consistency.

The most common symptoms of IBS-C include:

• Infrequent bowel movements
• Lumpy or hard stools
• Straining when passing a bowel movement
• A feeling of blockage in the anus or rectum.

IBS with Diarrhea (IBS-D)

IBS with diarrhea is the most common form of IBS. For your IBS to be classified as IBS-D, it requires more than 25% of your stools to be loose and less than 25% hard and lumpy. If you have ISB-D, you may feel like you need to go to the toilet more frequently.

People with IBS-D experience the following symptoms regularly:

• Frequent bowel movements
• Loose stools
• Feelings of urgency.

IBS with Mixed bowel habits (IBS-M)

IBS with mixed bowel habits (IBS-M), is also known as IBS with alternating bowel habits (IBS-A). In this form of IBS, bowel habits are not consistent. If you have IBS-M, you may find that stools are both lumpy and hard, and at other times loose and watery. You may experience changes in your stools and bowel habits on a weekly or even daily basis.

For your condition to be diagnosed as IBS-M, your stools must be both hard and lumpy, as well as loose in consistency at least 25% of the time.

IBS Unclassified (IBS-U)

The final IBS subtype may come with a mixed bag of symptoms. IBS-U is diagnosed if you have met the criteria for IBS but your symptoms don’t fall into the IBS-C, IBS-D or IBS-M categories.

Post-infectious IBS

Aside from the main four types of IBS, there are other ways we can classify this condition.

Post-infectious IBS happens when symptoms of IBS begin after a bout of gastro (gastroenteritis).

Following an infection, you may have chronic inflammation along with issues of gut flora and intestinal permeability which is thought to cause post-infectious IBS. The most common symptoms of post-infectious IBS include abdominal pain, diarrhea, and vomiting.

Up to one-third of people who experience a gastrointestinal infection develop IBS and half of these may recover within six years. Treatment of the underlying inflammation that’s causing the IBS symptoms may be necessary.

Post-diverticulitis IBS

As the name suggests, post-diverticulitis IBS occurs after symptoms of diverticulitis. If you have had diverticulitis you may be at an increased risk of developing IBS.

Diverticulitis occurs when small bulges or pockets develop in the lining of the intestine. When diverticula causes symptoms, such as stomach pain, it’s called diverticular disease. If the symptoms become more severe, it’s called diverticulitis. Symptoms of diverticulitis come and go, and may last only a few days.

Managing IBS symptoms

No matter which subtype of IBS you are experiencing, there are several management tools that can help you reduce symptoms.

Both over-the-counter and prescription medications are available to treat symptoms of IBS-C and IBS-D.  However, the number of subtypes makes it difficult for doctors to find therapies that will work with all IBS patients all the time. Some medications work for people with IBS constipation, while others work well for people with diarrhea as their main complaint.

If medication isn’t working for you, or you would prefer to manage your IBS without drugs, there are several other options available including hypnotherapy for IBS, and the low FODMAP diet.

Medications for IBS-C

Medications for IBS-C generally aim to reduce abdominal pain and increase the movement of food through the gastrointestinal tract to reduce constipation. These medications include:

• Lubiprostone (Amitiza) increases fluid secretion in the small intestine to improve motility, the speed of transit of stools through the digestive tract. It’s approved for people with IBS-C and is generally prescribed when a person has not responded to other treatments.
• Linaclotide (Linzess) increases fluid secretion in your small intestine to increase motility and help you pass a stool. It may cause diarrhea as a side effect.
• Antidepressants (SSRIs) such as fluoxetine (Prozac) or paroxetine (Paxil) may help to reduce abdominal pain and constipation.
• Laxatives available over-the-counter, such as magnesium hydroxide oral or polyethylene glycol (Miralax) may help to improve motility.

Medications for IBS-D

Medications for IBS-D generally aim to reduce abdominal pain and slow the movement of material through the digestive system to alleviate diarrhea. These medications include:

• Alosetron (Lotronex) relaxes the large intestine to reduce motility. Alosetron is intended for severe cases of IBS-D in women who haven't responded to other treatments, and is not approved for use by men.
• Antidepressants (tricyclics) which include imipramine (Tofranil) and desipramine (Norpramin) may be prescribed in low doses to reduce abdominal pain and improve diarrhea-predominant IBS. Side effects include drowsiness, blurred vision, dizziness and dry mouth.

Rifaximin (Xifaxan) an antibiotic that may decrease bacterial overgrowth and diarrhea in IBS-D.

Psychological management of IBS

Several psychological approaches have been shown to improve symptoms of IBS. This doesn’t mean that IBS is ‘all in your head’, rather these approaches restore the connection between the brain and the gut, to reduce symptoms.

The most common psychological treatments for IBS are:

• Hypnotherapy can help you to restore the connection between the brain and the gut. Several studies have confirmed that hypnotherapy is one of the most effective approaches to improving symptoms of IBS such as abdominal pain, in fact, it has been shown to reduce symptoms in 70% of patients.

• Cognitive behavioral therapy (CBT) is a type of talk therapy that may assist you to improve your thoughts and behaviors to think more positively. CBT involves understanding the connection between thoughts, feelings, and actions. Several studies have shown that CBT is effective in reducing symptoms of IBS.

• Yoga is an ancient practice that involves breathing and postural exercises. Yoga has been shown to improve symptoms of IBS by restoring signals between the brain and the gut, and lowering stress.

• Mindfulness meditation involves focusing on the present moment and limiting emotional reactions to judgments. Research shows that mindfulness meditation is effective in reducing stress and symptoms of IBS.

Dietary treatments for IBS

For many people with IBS, diet can play a significant role. Your doctor or nutritionist may recommend avoiding certain foods to help you avoid triggering symptoms of IBS. One group of foods your doctor may recommend are those containing high levels of FODMAPs. FODMAPs are short-chain carbohydrates found in many grains, fruits and vegetables that have been shown to worsen IBS symptoms. The low-FODMAP diet involves removing these foods, and was developed by Monash University to treat symptoms of IBS.

The Wrap Up

While all forms of IBS are similar, each presents in slightly different ways including constipation, diarrhea, or a combination of the two. People who have experienced gastroenteritis or diverticulitis may also experience IBS symptoms. No matter which form of IBS you experience, management can include medication, dietary changes or psychological therapies such as hypnotherapy for IBS. Make sure you speak to your doctor to work out which management will work best for you.