1. Digestive Disease Myths Slideshow Pictures
2. Take the Quiz: Tummy Trouble Digestive Disorders
3. Diverticulitis (Diverticulosis) Slideshow Pictures

Medical Author:

Adam Schoenfeld, MD

Medical Author:

George Y. Wu, MD, PhD

Medical Editor:

Jay W. Marks, MD

Jay W. Marks, MD

Jay W. Marks, MD, is a board-certified internist and gastroenterologist. He graduated from Yale University School of Medicine and trained in internal medicine and gastroenterology at UCLA/Cedars-Sinai Medical Center in Los Angeles.

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In this Article

• Crohn's disease facts
• What is Crohn's disease?
• What causes Crohn's disease?
• How does Crohn's disease affect the intestines?
• How is Crohn's disease different from ulcerative colitis?
• What are the symptoms of Crohn's disease?
• What are the complications of Crohn's disease?
• How is Crohn's disease diagnosed?
• How is Crohn's disease treated?
• Crohn's Disease Medications
• Anti-inflammatory medications
• 5-ASA (mesalamine) oral medications
• 5-ASA rectal medications (Rowasa, Canasa)
• Corticosteroids
• Budesonide (Entocort EC)
• Antibiotics
• Immuno-modulator medications
• Azathioprine (Imuran) and 6-mercaptopurine (6-MP, Purinethol)
• Infliximab (Remicade)
• Adalimumab (Humira)
• Certolizumab pegol (Cimzia)
• Natalizumab (Tysabri)
• Methotrexate
• Surgery in Crohn's disease
• Are there any recommendations for diet and supplementation for Crohn's disease?
• Conclusions
• Pictures of Digestive Disease Myths - Slideshow
• Take the Quiz: Tummy Trouble Digestive Disorders
• Pictures of Diverticulitis (Diverticulosis) - Slideshow
• Patient Comments: Crohn's Disease - Diet
• Patient Comments: Crohn's Disease - Medications
• Patient Comments: Crohn's Disease - Symptoms
• Find a local Gastroenterologist in your town
• Crohn's Disease Index

While ulcerative colitis causes inflammation only in the colon (colitis) and/or the rectum (proctitis), Crohn's disease may cause inflammation in the colon, rectum, small intestine (jejunum and ileum), and, occasionally, even the stomach, mouth, and esophagus.

The patterns of inflammation in Crohn's disease are different from ulcerative colitis. Except in the most severe cases, the inflammation of ulcerative colitis tends to involve the superficial layers of the inner lining of the bowel. The inflammation also tends to be diffuse and uniform (all of the lining in the affected segment of the intestine is inflamed.)

Unlike ulcerative colitis, the inflammation of Crohn's disease is concentrated in some areas more than others, and involves layers of the bowel that are deeper than the superficial inner layers. Therefore, the affected segment(s) of bowel in Crohn's disease often is studded with deeper ulcers with normal lining between these ulcers.

Common symptoms of Crohn's disease include abdominal pain, diarrhea, and weight loss. Less common symptoms include poor appetite, fever, night sweats, rectal pain, and occasionally rectal bleeding. The symptoms of Crohn's disease are dependent on the location, the extent, and the severity of the inflammation. The different subtypes of Crohn's disease and their symptoms are:

1. Crohn's colitis is inflammation that is confined to the colon. Abdominal pain and bloody diarrhea are the common symptoms. Anal fistulae and peri-rectal abscesses also can occur.
2. Crohn's enteritis refers to inflammation confined to the small intestine (the first part, called the jejunum or the second part, called the ileum). Involvement of the ileum alone is referred to as Crohn's ileitis. Abdominal pain and diarrhea are the common symptoms. Obstruction of the small intestine also can occur.
3. Crohn's terminal ileitis is inflammation that affects only the very end of the small intestine (terminal ileum), the part of the small intestine closest to the colon. Abdominal pain and diarrhea are the common symptoms. Small intestinal obstruction also can occur.
4. Crohn's entero-colitis and ileo-colitis are terms to describe inflammation that involve both the small intestine and the colon. Bloody diarrhea and abdominal pain are the common symptoms. Small intestinal obstruction also can occur.

Crohn's terminal ileitis and ileo-colitis are the most common types of Crohn's disease. (Ulcerative colitis frequently involves only the rectum or rectum and sigmoid colon at the distal end of the colon. These are called ulcerative proctitis and procto-sigmoiditis, respectively.)

Up to one-third of patients with Crohn's disease may have one or more of the following conditions involving the anal area:

1. Swelling of the tissue of the anal sphincter, the muscle at the end of the colon that controls defecation.
2. Development of ulcers and fissures (long ulcers) within the anal sphincter. These ulcers and fissures can cause bleeding and pain with defecation.
3. Development of anal fistulae (abnormal tunnels) between the anus or rectum and the skin surrounding the anus). Mucous and pus may drain from the openings of the fistulae on the skin.
4. Development of peri-rectal abscesses (collections of pus in the anal and rectal area). Peri-rectal abscesses can cause fever, pain and tenderness around the anus.