Inflammatory Bowel Disease (IBD): Ulcerative Colitis, Crohn's Disease

Inflammatory bowel disease (IBD) is a common condition affecting more than one million people in the United States. This disease has two components:

  • Ulcerative colitis: the inflammation of the innermost lining of the large intestine and/or rectum.
  • Crohn's disease: the inflammation of the lining and walls of the large and/or small intestine. It also may affect other parts of the digestive system and can spread deep into the tissue.

Comparing Ulcerative Colitis and Crohn's Disease

Traditionally, these two conditions were thought to be distinct types of IBD. However, researchers are beginning to think of IBD as a spectrum (or range) of diseases that affect the intestines.

Thus, some people may only have symptoms of ulcerative colitis or symptoms of Crohn's disease, while others may have symptoms of both conditions (known as "indeterminate colitis").

Crohn's disease and ulcerative colitis share many similar symptoms and these symptoms may come and go (relapse and remit) and/or be worsened by stress.

The diseases have a genetic component with approximately 15% to 30% of people with IBD having a family member with the condition. Typically, people are first diagnosed with IBD in their late teens to early twenties, but people may develop the condition at any age.

Both conditions are associated with an increased lifetime risk for colorectal cancer.

While the majority of patients with IBD will never develop colorectal cancer, it is important to attend regular checkups and screenings for cancer.


The most common symptoms of Crohn's disease are diarrhea and abdominal pain, usually on the left lower side of the abdomen. In more severe cases of Crohn's disease, the inflammation may cause stricturing (a narrowing of the intestines caused by excess scar tissue) and fistulas (inflammatory tunnels that burrow through the intestines to either the skin or the bladder).

Ulcerative colitis most often causes bloody diarrhea that doesn't stop, abdominal cramps, and rectal bleeding.

Both conditions may cause anemia, nausea, vomiting, fever, weight loss, joint pain, and skin problems.


Diagnosis is based on symptoms, physical examination, blood tests for anemia or high levels of white blood cells, and a sample of a bowel movement (stool sample).

Imaging studies to view the gastrointestinal tract may also be used, including x-rays, sigmoidoscopy, and colonoscopy. In the latter two tests, your doctor will insert an endoscope (a thin, flexible tube equipped with a light and camera) into your rectum to view your large intestine. A sigmoidoscopy is used to see the lower part of the large intestine, while a colonoscopy is used to see the entire large intestine. If necessary, the doctor may take a small tissue sample (biopsy) from the lining of the intestine.


While there is no cure for inflammatory bowel disease (IBD), lifestyle changes, medications, and surgery may help reduce the signs and symptoms of IBD and help bring about remission (a period of time when symptoms fade).

Diet and Lifestyle Changes

Nutritionists can help determine what foods worsen your symptoms and how to modify your diet to meet your nutritional needs. Smoking cessation is important as smoking may cause and worsen IBD symptoms. In addition, because stress can worsen symptoms or bring about a relapse, stress reduction techniques are important. These include exercise, yoga, meditation, massage, breathing exercises, biofeedback, support groups, and therapy.


A variety of medications are available to help manage the symptoms of IBD and try to keep the disease in remission. Treatment often starts with anti-inflammatory agents and antibiotics and may progress to corticosteroids in more severe cases. Because of the side effects linked to corticosteroids, these agents are only used for a short time – two to three months –to limit patients' exposure.

Immunologic agents are used to suppress the overactive immune system in the gut and help lower the dose or keep patients off of steroids. These are used less often in Crohn's disease than in ulcerative colitis.

In the past, biologics were used after a failure of response to corticosteroids or immunomodulators, but now researchers are evaluating use of these agents in select patients earlier. Doctors are cautious in using biologics because of their side effects, but in select patients with severe disease, biologics may limit or prevent the need for corticosteroids.


Surgery can greatly restore quality of life in people who are struggling to get better despite medical treatment. Also, some people may benefit from surgery without needing to be exposed to potentially harmful side effects of medications.

The majority of elective colon and rectal surgeries can be performed laparoscopically, meaning through a small incision, which reduces healing time, pain, and hospital stay.

A resection is used for isolated Crohn's disease that affects only a small area of the intestine. The surgeon will cut above and below the diseased area, remove a section of the intestine, and reconnect the two areas.

Short areas of stricturing in Crohn's disease can be treated with a procedure called a strictureplasty, which opens that narrowing in a way that restores flow of intestinal contents and allows nutrients to be absorbed. When stricturing is more extensive (over a greater area), a side-to-side isoperistaltic strictureplasty may be needed. This technique was developed by Dr. Fabrizio Michelassi, the surgeon-in-chief at NewYork-Presbyterian/Weill Cornell, and alleviates symptoms while preserving as much intestine as possible.

A proctocolectomy — removal of the entire colon and rectum — is the most common surgery for ulcerative colitis and is considered curative. The end of the small intestine is connected to a small opening surgically created in the abdominal wall (an ileostomy or stoma) that allows waste to drain into a bag attached outside of the body. In an ileoanal anastomosis, also called a pull-through operation or a J pouch, the colon and rectum are removed and the end of the small intestine is surgically altered to form a J-shaped pouch that connects to the anus. While the J-pouch is healing, waste is temporarily removed through an ileostomy.


Digestive and Liver Diseases


Center for Advanced Digestive Care
NewYork-Presbyterian/Weill Cornell