Inflammatory bowel disease

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at April 19, 2016
StartDiseasesInflammatory bowel disease

Inflammatory bowel disease (IBD) includes a number of conditions that affect the gastrointestinal tract of the human body. This category of illness consists of both ulcerative colitis and Crohn’s disease. Conditions such as irritable bowel syndrome are considered separate from the inflammatory bowel disease category.


Definition & Facts

An estimated 1.6 million people in the United States suffer from inflammatory bowel disease. About 70,000 new cases are diagnosed each year. Though the exact causes of inflammatory bowel disease are unknown, genetic factors and changes in gut flora, the microorganisms that inhabit the human intestines may cause IBD.

These conditions cannot be cured, but effective treatments are available to help individuals live more effectively with the disease. IBD encompasses two major illnesses:

  • Ulcerative colitis – Ulcerative colitis affects only the large intestine and the rectum, the lowest part of the intestines. Inflammation develops in the innermost lining of the colon. It can begin in the rectum and gradually affect the entire large intestine.
  • Crohn’s disease – Crohn’s disease can affect any part of the digestive tract, from the mouth all the way to the anus. It frequently attacks the ileum, that is, the part of the small intestine where it joins the large intestine. Inflammation can be seen in all layers of the gastrointestinal wall, and it may occur in patches of the intestines, affecting some parts but not others.

Symptoms & Complaints

Ulcerative colitis symptoms include abdominal pain, cramping, diarrhea, fever, unexplained weight loss, fatigue, inability to defecate even with urgency, rectal bleeding, blood in stool, or pus in stool.

Crohn’s disease can cause diarrhea, abdominal pain, cramping, fatigue, fever, weight loss, blood in the stools, mouth sores and rectal discomfort. It can also cause inflammation of the eyes, joint inflammation, and skin inflammation.

Complications of IBD may involve liver diseases such as hepatitis, diseases of the pancreas such as pancreatitis, gallbladder diseases such as gallstones, and primary sclerosing cholangitis which scars the bile ducts. In children, the disease can cause delays in growth or sexual development.


The underlying causes of the development of inflammatory bowel disease are not well understood. However, research suggests that certain genes may play a part in the development of the condition. Dysfunction in the immune system is also associated with the disease. As the body attempts to fight disruptions in the bacteria and viruses in the digestive tract, it may also begin to attack the tissues of the intestine wall itself.

Problems with diet and stress management can also contribute to the onset of these diseases. IBD can occur in any racial group. However, those of Ashkenazi Jewish descent appear to be at higher risk for this condition. Individuals who have asthma or chronic obstructive pulmonary disease (COPD) are also at higher risk for these conditions. Inflammatory bowel diseases cause visible areas of inflammation and lesions in the colon and other parts of the digestive tract.

Diagnosis & Tests

Blood tests can show whether the patient has anemia. Blood tests can also show the presence of white blood cells, which may indicate infection. A stool sample helps the physician determine if infection is present in the digestive system. A colonoscopy uses a tiny camera in a flexible tube to directly view the lining of the colon. A biopsy of tissue may also be taken for laboratory analysis.

Sigmoidoscopy also uses a flexible tube to view the lower part of the color and may be used when other parts of the colon are too inflamed to allow a full colonoscopy. X-rays of the abdomen can help to rule out other conditions. A CT scan may be ordered to determine how much of the colon is affected by the disease.

Treatment & Therapy

Treatment for inflammatory bowel disease involves a number of different approaches. First, physicians work to reduce the severity of symptoms so that patients can function normally in their everyday lives. The goal of achieving complete remission can be pursued with a number of medications, such as azathioprine, mercaptopurine, and corticosteroid drugs. Antibiotics may be given to eliminate infection that may occur. In addition, treatment will also attempt to prevent flare-ups of inflammation with immunosuppressant medications.

Surgery is sometimes needed to remove intestinal tissue that has been injured by chronic inflammation. In some cases, physicians may choose to provide milder drugs initially, gradually moving toward more powerful medications as the need arises. In other cases, physicians may initially prescribe the most powerful medications, gradually prescribing milder maintenance drugs.

More common medications may also be used to treat symptoms, such as anti-diarrheal medicine, fiber supplements, over-the-counter pain relievers, iron supplements, calcium supplement, and vitamin D supplements or vitamin B-12 injections. Special diets or feeding methods may also be needed during treatment.

Prevention & Prophylaxis

Because smoking is thought to affect the risk for Crohn’s disease, doctors may prescribe smokers a smoking cessation program or medications that can help them stop. Because flare-ups of inflammation in the colon and other parts of the intestinal tract are common features of these diseases, doctors can provide a program of ongoing care to reduce the number and severity of flare-ups.

In general, a lifestyle that supports good health and a well-functioning immune system in recommended. It can be helpful to eat a varied diet that includes whole grains; lean meats; omega-3 fats such as olive oil and canola; fruits and vegetables without seeds or skin; low-fat dairy products and carbohydrates that have soluble fiber, such as oat bran and legumes. Drinking plenty of water throughout the day is also important.