Overview of Inflammatory Bowel Disease

Crohn disease and ulcerative colitis both affect organs other than the intestines. Most extraintestinal manifestations are more common in ulcerative colitis and Crohn colitis than in Crohn disease limited to the small bowel. Extraintestinal manifestations of inflammatory bowel disease are categorized in 3 ways:

1. Disorders that usually parallel (ie, wax and wane with) IBD flare-ups: These disorders include peripheral arthritis, episcleritis Episcleritis Episcleritis is self-limiting, recurring, usually idiopathic inflammation of the episcleral tissue that does not threaten vision. Symptoms are a localized area of hyperemia of the globe, irritation... read more , aphthous stomatitis Recurrent Aphthous Stomatitis Recurrent aphthous stomatitis (RAS) is a common condition in which round or ovoid painful ulcers recur on the oral mucosa. Etiology is unclear. Diagnosis is clinical. Treatment is symptomatic... read more , and erythema nodosum Erythema Nodosum Erythema nodosum is a specific form of panniculitis characterized by tender, red or violet, palpable, subcutaneous nodules on the shins and occasionally other locations. It often occurs with... read more . Arthritis tends to involve large joints and be migratory and transient.

2. Disorders that are clearly associated with IBD but appear independently of IBD activity: These disorders include ankylosing spondylitis, Ankylosing Spondylitis Ankylosing spondylitis is the prototypical spondyloarthropathy and a systemic disorder characterized by inflammation of the axial skeleton, large peripheral joints, and digits; nocturnal back... read more sacroiliitis, uveitis Overview of Uveitis Uveitis is defined as inflammation of the uveal tract—the iris, ciliary body, and choroid. However, the retina and fluid within the anterior chamber and vitreous are often involved as well.... read more , pyoderma gangrenosum Pyoderma Gangrenosum Pyoderma gangrenosum is a chronic, neutrophilic, progressive skin necrosis of unknown etiology often associated with systemic illness and sometimes skin injury. Diagnosis is clinical. Treatment... read more , and primary sclerosing cholangitis Primary Sclerosing Cholangitis (PSC) Primary sclerosing cholangitis (PSC) is patchy inflammation, fibrosis, and strictures of the bile ducts that has no known cause. However, 80% of patients with PSC also have inflammatory bowel... read more . Ankylosing spondylitis occurs more commonly in IBD patients with human leukocyte antigen B27 (HLA-B27). Most patients with spinal or sacroiliac involvement have evidence of uveitis and vice versa. Primary sclerosing cholangitis, which is a risk factor for cancer of the biliary tract, is strongly associated with ulcerative colitis and Crohn colitis. Cholangitis may appear before or concurrently with the bowel disease or even 20 years after colectomy. Liver disease (eg, steatotic liver disease, autoimmune hepatitis, pericholangitis, cirrhosis) occurs in 3 to 5% of patients, although minor abnormalities in liver tests are more common. Some of these conditions (eg, primary sclerosing cholangitis) may precede IBD by many years and, when diagnosed, should prompt an evaluation for IBD.

3. Disorders that are consequences of disrupted bowel physiology: These disorders occur mainly in severe Crohn disease of the small bowel. Malabsorption Overview of Malabsorption Malabsorption is inadequate assimilation of dietary substances due to defects in digestion, absorption, or transport. Malabsorption can affect macronutrients (eg, proteins, carbohydrates, fats)... read more may result from extensive ileal resection and cause deficiencies of fat-soluble vitamins, vitamin B12, or minerals, resulting in anemia, hypocalcemia, hypomagnesemia, clotting disorders, and bone demineralization. In children, malabsorption retards growth and development. Other disorders include kidney stones resulting from excessive dietary oxalate absorption, hydroureter and hydronephrosis resulting from ureteral compression by the intestinal inflammatory process, gallstones resulting from impaired ileal reabsorption of bile salts, and amyloidosis secondary to long-standing inflammatory and suppurative disease.

Thromboembolic disease may occur as a result of multiple factors in all 3 categories.

Several classes of medications are helpful for IBD. Details of their selection and use are discussed under each disorder and in Medications for Inflammatory Bowel Disease Medications for Inflammatory Bowel Disease Several classes of medications are helpful for inflammatory bowel disease (IBD). Details of their selection and use are discussed under each disorder (see Crohn disease treatment and ulcerative... read more .

The following English-language resources may be useful. Please note that THE MANUAL is not responsible for the content of these resources.