IBD and IBS are Not the Same Thing

Patient Expert

The acronyms are similar, as are some of the symptoms, but contrary to common belief Inflammatory Bowel Disease (IBD) and Irritable Bowel Syndrome (IBS) are not the same thing.

Irritable Bowel Syndrome affects approximately 55 million Americans (that's about 1 in 5 people) and is second only to the common cold for missed days from school and work. IBS is said to be a functional disorder of the intestines - functional meaning that the normal muscular contractions of the digestive tract become irregular and uncoordinated making it difficult for the intestines to process and eliminate waste correctly.

The improper functioning of the digestive tract can result in symptoms such as gas, bloating, abdominal distention, abdominal cramps, diarrhea and/or constipation, abdominal cramps. Other, less common symptoms of IBS include mucus in the stool, a feeling of incomplete evacuation after a bowel movement, and nausea. Blood tests, stool tests, colonoscopy, and small bowel series x-rays all come back normal. IBS is not a disease, but a functional disorder of the digestive tract that is diagnosed after all other possible disorders have been ruled out. Other disorders that can often be confused for IBS include, celiac disease, benign tumors, colon cancer, Crohn's disease, ulcerative colitis, diverticulitis, endometriosis, food poisoning, or food intolerances such as lactose intolerance.

In IBS there are no physical signs of damage or disease in the tissues of the bowel.

However, in patients who have Inflammatory Bowel Disease (IBD) the tissues of the intestines are inflamed and/or ulcerated. Patients who have IBD are diagnosed either with Ulcerative Colitis or Crohn's disease. And IBD is thought to be an auto-immune disorder.

Symptoms indicative of IBD include diarrhea, blood in the stool, and weight loss. Blood tests often show IBD patients are low in iron, and an ESR, or Erythrocyte sedimentation rate which is a marker for inflammation, tends to be elevated. Stool studies in the patient with IBD will often show occult blood (not visible to the naked eye) as well as white blood cells. And a colonoscopy or small bowel series show abnormalities.

Below are portions of the clinical descriptions of Ulcerative Colitis (UC) and Crohn's Disease from the web site of the Crohn's and Colitis Foundation of America.

"Ulcerative colitis is a chronic (ongoing) disease of the colon, or large intestine. The disease is marked by inflammation and ulceration of the colon mucosa, or innermost lining. Tiny open sores, or ulcers, form on the surface of the lining, where they bleed and produce pus and mucus. Because the inflammation makes the colon empty frequently, symptoms typically include diarrhea (sometimes bloody) and often crampy abdominal pain.

The inflammation usually begins in the rectum and lower colon, but it may also involve the entire colon. When ulcerative colitis affects only the lowest part of the colon -- the rectum -- it is called ulcerative proctitis. If the disease affects only the left side of the colon, it is called limited or distal colitis. If it involves the entire colon, it is termed pancolitis."

"Crohn's disease is a chronic (ongoing) disorder that causes inflammation of the digestive or gastrointestinal (GI) tract. Although it can involve any area of the GI tract from the mouth to the anus, it most commonly affects the small intestine and/or colon.

Because Crohn's and UC are so similar, it is sometimes difficult to establish the diagnosis definitively. In fact, approximately 10 percent of colitis cases are unable to be pinpointed as either ulcerative colitis or Crohn's disease and are called indeterminate colitis.

Both illnesses do have one strong feature in common. They are marked by an abnormal response by the body's immune system. The immune system is composed of various cells and proteins. Normally, these protect the body from infection. In people with Crohn's disease, however, the immune system reacts inappropriately. Researchers believe that the immune system mistakes microbes, such as bacteria that is normally found in the intestines, for foreign or invading substances, and launches an attack. In the process, the body sends white blood cells into the lining of the intestines, where they produce chronic inflammation. These cells then generate harmful products that ultimately lead to ulcerations and bowel injury. When this happens, the patient experiences the symptoms of IBD.

Although Crohn's disease most commonly affects the end of the small intestine (the ileum) and the beginning of the large intestine (the colon), it may involve any part of the GI tract. In ulcerative colitis, on the other hand, the GI involvement is limited to the colon. In Crohn's disease, all layers of the intestine may be involved, and there can be normal healthy bowel in between patches of diseased bowel. In contrast, ulcerative colitis affects only the superficial layers (the mucosa) of the colon in a more even and continuous distribution, which starts at the level of the anus."

While this web site is specifically for patient's who have IBD, patient's who have IBS can find more information and support at web sites like www.ibsgroup.org.

Next week I will discuss some of the more common treatment options being used to treat Inflammatory Bowel Disease.