What You Need To Know About IBS With Constipation (IBS-C)

Irritable bowel syndrome (IBS) affects between 7% and 16% of adults in the US, with women most affected.¹ One of the most common symptoms of IBS is constipation.

However, standalone chronic constipation is also frequent, with 2% to 27% of people of all ages in the US diagnosed with constipation. It’s three times more likely to affect women than men.² ³

Because of these overlaps, it can be difficult for doctors to determine whether you have constipation or constipation-predominant IBS (IBS-C).

Read on to find out how to distinguish between regular constipation and IBS-C. We’ll explain the signs, symptoms, and how to manage IBS-C.

Types of irritable bowel syndrome

The development of the four subtypes is similar, and the main symptom determines the subtype diagnosis. As its name suggests, in IBS with constipation (IBS-C), constipation is the predominant symptom.¹

Symptoms of IBS with constipation

In all IBS types, the primary symptom is abdominal pain, which usually affects the mid or lower abdomen. Pain can be cramping, burning, stabbing, or aching in nature. Most importantly, pain is related to bowel movements (pooping). In IBS-C, abdominal discomfort often decreases after a bowel movement or after passing gas.

Some other common symptoms of IBS-C are:⁵

• Bloating that can be painful

• Excessive gas production

• Feeling like your bowels are not completely cleared after going to the toilet (i.e., feeling like there’s something left behind)

• Stools (poops) that are hard, lumpy, or resembling little pellets

• Difficulty going to the toilet

A telephone review of 350 people diagnosed with IBS-C found the most common complaints involved episodes of gas, bloating, abdominal pain, straining on the toilet, incomplete evacuation of stool with a bowel movement, and infrequent stool. Patients reported episodes of gas, bloating, and abdominal pain occurring over 200 times per year on average. They also reported straining, irregular stool, and incomplete bowel evacuation between 100 to 150 times per year.⁵

What causes IBS with constipation?

IBS-C’s precise cause is unknown, and it’s most likely multifactorial, meaning many different factors contribute to the condition. Researchers have identified some of the mechanisms underlying IBS-C.

One of the potential causes of IBS may be gut inflammation. This leads to activated gut immune cells, which interfere with normal serotonin regulation.

Serotonin modulates the sensory and motor functions of the gut, including how sensitive the colon is to pain stimuli and the transit time through the gut (digestion). Serotonin secretion can become dysregulated. This can result in a hypersensitive gut with a very slow transit time, which can cause uncomfortable or painful constipation.¹

As a result of the slowed transit time of stool in the colon, the body reabsorbs water back into the body, leaving stool hard and dried out, which worsens constipation.⁵

An altered gut microbiome may also play a role in symptoms. Bacterial breakdown of fermentable fiber can increase gas production.⁶

There is also a genetic component to IBS, so if other people in your family have IBS-C, you are more likely to develop it.⁶

What is the difference between IBS-C and regular constipation?

The major difference between IBS-C and regular constipation (also called chronic functional constipation or chronic idiopathic constipation) is that the abdominal pain and bloating associated with IBS-C are more severe and chronic than regular constipation.

If you have IBS with constipation, you are more likely to have periods of regular bowel movements between IBS flare-ups.

Lately, the scientific community has recognized significant overlap between IBS-C and chronic constipation; the two disorders may represent varying degrees of the same spectrum.⁷

How is IBS with constipation diagnosed?

Your doctor will take a symptom history from you to make a diagnosis of IBS. Doctors use the Rome IV criteria to diagnose IBS based on symptoms and frequency: Table 1¹ summarises the criteria.

As well as taking an extensive symptom history, your doctor will likely do a physical examination and take some blood tests and a stool sample. The blood tests and stool samples exclude other conditions, such as inflammatory bowel disease and colorectal cancer, which can present similarly to IBS-C.

Treating IBS with constipation

Currently, IBS doesn’t have a cure, so treatment focuses on managing symptoms.

Dietary modifications

Many people who suffer from IBS find that specific foods trigger their symptoms, and high-FODMAP foods are a common culprit. It may be beneficial to follow a low-FODMAP diet if you suffer from IBS-C.

Low-FODMAP diets can decrease IBS symptoms, but they are very restrictive, so you should undertake them with professional guidance.⁸

Increasing intake of soluble fiber, such as the fiber found in oatmeal and potatoes, can improve IBS-C symptoms. Soluble fiber forms a viscous gel in the colon that helps to soften and lubricate the stool.

Lifestyle modifications

Exercise, stress, adequate hydration, and sleep all play a role in IBS. The symptoms of IBS-C can be alleviated by exercise, while poor or disrupted sleep can exacerbate IBS flare-ups. Reducing stress using mindfulness techniques and meditation can manage symptoms.⁹

Medication

If you are taking any medications that can cause constipation, they may well worsen your IBS-C symptoms. These include opiates, codeine, anti-inflammatories, water pills, and iron and calcium supplements. Speak to your doctor if you think your medication could be worsening your IBS-C.¹⁰

Fiber

Psyllium husk is commonly used for IBS-C, and it’s effective in increasing stool frequency and softening stools. Prunes and prune fiber can improve symptoms of IBS-C.¹⁰

Peppermint oil

Peppermint oil can provide some relief for abdominal cramping.¹⁰

Prescription medication

If symptoms are severe and lifestyle and dietary modifications don’t help, you may need prescription medication, including Linaclotide, Lubiprostone, Plecanatide, Tegaserod, and Tenapanor. These are all approved for treating IBS-C, but they are specialized and individualized, so doctors don’t typically recommend them as first-line therapies.¹⁰

While there is anecdotal evidence supporting Selective Serotonin Reuptake Inhibitors (SSRIs), the FDA has not approved them for IBS. The evidence supporting this treatment is poor, and the American College of Gastroenterologists doesn’t recommend them.¹⁰

Be careful of using antispasmodics for IBS with constipation. Although they may alleviate some of the pain and cramping associated with IBS with diarrhea, they can cause constipation, so those with IBS-C should not use them.¹⁰

The lowdown

There are four subtypes of irritable bowel syndrome (IBS):

• IBS with constipation (IBS-C)

• IBS with diarrhea (IBS-D)

• IBS with both constipation and diarrhea (IBS-M)

• Unsubtyped IBS

Constipation is the primary symptom in IBS-C. Other symptoms of IBS-C include abdominal pain, bloating, hard and infrequent stools, and feelings of incompletely emptying your bowels after going to the toilet.

Abdominal pain is the main symptom that differentiates IBS-C from regular constipation. It’s diagnosed largely on your symptom history. Your doctor may also examine you and request some blood tests and a stool sample.

Management of IBS-C works on controlling and lessening symptoms. Potential dietary modifications include the addition of foods high in non-fermentable fiber and following a low-FODMAP diet. You might also find soluble fiber supplements, such as psyllium and prune fiber, beneficial in softening and hydrating your stool.

Exercise can ease symptoms of IBS-C, and you might find meditation useful in reducing IBS-C flare-ups. Peppermint oil can relieve cramps.

If first-line management is ineffective, you may need to chat to your doctor about trying a prescription medication. SSRIs and antispasmodics have limited use.