Inflammatory Bowel Disease vs. Irritable Bowel Syndrome – Knowing the Differences between the Two

By Jennifer Engels, MD

Inflammatory bowel disease and irritable bowel syndrome are two distinct gastrointestinal disorders, but the differences between them can be confusing. While they have many of the same symptoms, they are not the same condition. Consequently, it’s essential to know the differences between the two and to get the proper diagnosis so that you can manage your condition.

Inflammatory bowel disorder (IBD)

Inflammatory bowel disease is classified as a structural disease, meaning that physical damages causes the symptoms that patients suffer. In addition, IBD actually refers to two different chronic conditions or diseases that may be related. These are Crohn’s disease and ulcerative colitis. Both of these diseases consist of inflammation of the intestines, leading to a bowel that is inflamed, swollen and that may develop ulcers. This inflammation produces various degrees of abdominal discomfort, diarrhea and intestinal bleeding, and both Crohn’s disease and ulcerative colitis can result in serious digestive problems.

IBD – Crohn’s disease

Crohn’s disease can involve any part of the GI tract from the mouth to the anus. However, it most commonly affects the end of the small intestine – known as the ileum – where it joins the colon. Crohn’s disease may also appear in “patches,” affecting some areas of the GI tract while leaving other areas untouched. And in some cases of Crohn’s disease, the inflammation may extend through the entire thickness of the bowel wall.

IBD – Ulcerative colitis

In contrast to Crohn’s disease, ulcerative colitis is limited to the colon (large intestine) and the rectum. The inflammation usually begins in the rectum and lower colon but may spread continuously to involve the entire colon.

Symptoms of IBD

The symptoms of IBD vary from person to person, may change over time, and can range from mild to severe. People with IBD can also go through periods of remission when the disease is quiet, alternating with times when the disease flares and causes symptoms.

IBD symptoms related to the GI tract include:

• Diarrhea
• Abdominal pain
• Urgent need to move the bowels
• Rectal bleeding
• A sensation of incomplete bowel movement

General symptoms that may also be associated with IBD include:

• Fever
• Loss of appetite
• Weight loss
• Fatigue
• Night sweats
• Interruption of normal menstrual cycles

While the symptoms of Crohn’s disease and ulcerative colitis are similar, they are not quite the same. Pain, nausea and vomiting, and abdominal enlargement are more common with Crohn’s disease because the entire bowel wall is inflamed. In contrast, there tends to be more bleeding associated with ulcerative colitis because of the extensive erosion by inflammation of the blood vessels supplying the lining of the colon.

Causes of IBD

While the exact cause of IBD is not entirely understood, it is known to involve an interaction between your genetic makeup, your immune system and environmental factors. Under normal conditions, the immune system usually attacks and kills invaders, such as bacteria, viruses, fungi and other microorganisms. But in cases of IBD, the immune system mounts an inappropriate response in the intestinal tract, leading to inflammation.

Diagnosis and treatment 

The diagnosis of IBD can be complex and may take considerable time. After collection of a patient’s medical history, diagnosis may involve a physical exam, blood tests and possible endoscopic procedures.

Because it is a chronic condition, an important part of IBD treatment involves careful management of the disease so that a patient has the best chance of recovery.

Patients may need antibiotics, antidiarrheal drugs, lifestyle changes such as stress reduction, and in the most extreme cases, perhaps surgery.

Irritable bowel syndrome

Irritable bowel syndrome (IBS) is classified as a functional GI disorder, meaning there is some type of disturbance in a person’s bowel function. In contrast to IBD, IBS does not cause inflammation and rarely requires hospitalization or surgery.

Symptoms of IBS

In addition to being a functional disorder, IBS is also classified as a syndrome, or collection of symptoms. Some of the more common include:

• Chronic and persistent abdominal pain
• Constipation alternating with diarrhea
• Mucus in the stool
• Gassiness
• Abdominal bloating, or the feeling of being full
• Abdominal swelling
• Nausea
• The urge to have a bowel movement without being able to go

Causes of IBS

As with IBD, the causes of IBS are not fully understood. Researchers believe that while stress can aggravate IBS, it is actually caused by a disturbance between the brain and the gut.

Stated briefly, the GI tract is controlled by a complex series of sensory and motor nerves that exchange information between the brain, spinal cord and nerves. During the normal digestive process, muscle contractions in the colon move food through your system, while absorbing water and nutrients to create the stool that is passed during a bowel movement.

With IBS, the necessary muscle contractions are not working as they should. The term “irritable” is used because the nerve endings in the bowel are unusually sensitive, and the nerves that control the muscles in the gut are unusually active.

Certain foods and medications, stress and hormonal changes can produce the symptoms associated with IBS, and the ensuing spasms can lead to either constipation, if the stool loses too much water, or to diarrhea by pushing the stool through your colon so fast that fluids cannot be absorbed.

Diagnosis and treatment

IBS is diagnosed based on your symptoms and the elimination of other causes. Your doctor may use blood and stool tests, x-rays, endoscopy and psychological tests to rule out other causes.

For treatment, patients may need dietary changes, addressing the gut microbiome (the balance of healthy and unhealthy microbes in the intestine), the use of stress reduction techniques, and possible psychological interventions.  Medications would be the last resort.

Treatment is available at We Care Frisco

Millions of people suffer from either IBD or IBS or both. But relief is available, and if you are suffering from GI problems that are interfering with the quality of your life, we urge you to schedule an appointment at We Care Frisco. Together, we will explore your symptoms and formulate a treatment plan to provide relief and restore your quality of life.