9 Signs and Symptoms of Irritable Bowel Syndrome (IBS)

Irritable bowel syndrome (IBS) affects between 6–18% of people worldwide. This condition involves changes in frequency or form of bowel movements and lower abdominal pain. Diet, stress, poor sleep and changes in gut bacteria may all trigger symptoms.

However, triggers are different for each person, making it difficult to name specific foods or stressors that everyone with the disorder should avoid.

This article will discuss the most common symptoms of IBS and what to do if you suspect you have it.

1. Pain and Cramping

Abdominal pain is the most common symptom and a key factor in diagnosis. Normally, your gut and brain work together to control digestion. This happens via hormones, nerves and signals released by the good bacteria that live in your gut.

In IBS, these cooperative signals become distorted, leading to uncoordinated and painful tension in the muscles of the digestive tract.

This pain usually occurs in the lower abdomen or the entire abdomen but is less likely to be in the upper abdomen alone. Pain typically decreases following a bowel movement.

Diet modifications, such as a diet low in FODMAPs, may improve pain and other symptoms. Other treatments include bowel relaxants like peppermint oil, cognitive behavior therapy and hypnotherapy.

For pain that doesn’t respond to these changes, a gastroenterologist can help you find a medication specifically proven to ease IBS pain.

2. Diarrhea

Diarrhea-predominant IBS is one of the three main types of the disorder. It affects roughly one-third of patients with IBS.

Accelerated bowel transit in IBS can also result in a sudden, immediate urge to have a bowel movement. Some patients describe this as a significant source of stress, even avoiding some social situations for fear of a sudden onset of diarrhea.

Additionally, stool in the diarrhea-predominant type tends to be loose and watery and may contain mucus.

3. Constipation

Although it seems counterintuitive, IBS can cause constipation as well as diarrhea. Constipation-predominant IBS is the most common type, affecting nearly 50% of people with IBS.

Altered communication between the brain and bowel may speed up or slow down the normal transit time of stool. When transit time slows, the bowel absorbs more water from stool, and it becomes more difficult to pass.

Constipation is defined as having fewer than three bowel movements per week.

“Functional” constipation describes chronic constipation not explained by another disease. Functional constipation is not related to IBS and is very common. Functional constipation differs from IBS in that it is generally not painful.

In contrast, constipation in IBS includes abdominal pain that eases with bowel movements.

Constipation in IBS also often causes a sensation of an incomplete bowel movement. This leads to unnecessary straining.

Along with the usual treatments for IBS, exercise, drinking more water, eating soluble fiber, taking probiotics and the limited use of laxatives may help.

4. Alternating Constipation and Diarrhea

Mixed or alternating constipation and diarrhea affects about 20% of patients with IBS.

Diarrhea and constipation in IBS involve chronic, recurring abdominal pain. Pain is the most important clue that changes in bowel movements are not related to diet or common, mild infections.

This type of IBS tends to be more severe than the others with more frequent and intense symptoms .

The symptoms of mixed IBS also vary more from one person to another. Therefore, this condition requires an individualized treatment approach rather than “one-size-fits-all” recommendations.

5. Changes in Bowel Movements

Slow-moving stool in the intestine often becomes dehydrated as the intestine absorbs water. In turn, this creates hard stool, which can exacerbate symptoms of constipation.

Prompt movement of stool through the intestine leaves little time for absorption of water and results in the loose stools characteristic of diarrhea.

IBS can also cause mucus to accumulate in stool, which is not usually seen in other causes of constipation. Blood in stool may be a sign of another, potentially serious medical condition and deserves a visit to your doctor. Blood in stool may appear red but often appears very dark or black with a tarry consistency.

6. Gas and Bloating

Altered digestion in IBS leads to more gas production in the gut. This can cause bloating, which is uncomfortable. Many with IBS identify bloating as one of the most persistent and nagging symptoms of the disorder.

Avoiding lactose and other FODMAPs can help reduce bloating.

7. Food Intolerance

Up to 70% of individuals with IBS report that particular foods trigger symptoms.

Two-thirds of people with IBS actively avoid certain foods. Sometimes these individuals exclude multiple foods from the diet.

Why these foods trigger symptoms is unclear. These food intolerances are not allergies, and trigger foods don’t cause measurable differences in digestion.

While trigger foods are different for everyone, some common ones include gas-producing foods, such as FODMAPs, as well as lactose and gluten.