crohn disease - digestive disorders - msd manual consumer version

7/24/2019 Crohn Disease - Digestive Disorders - MSD Manual Consumer Version

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ByAaron E. Walfish, MD, David B. Sachar, MD

Crohn disease (regional enteritis, granulomatous ileitis, or ileocolitis) is chronic inflammation of

the intestinal wall that typically involves the lower part of the small intestine, the upper part ofthe large intestine, or both but may affect any part of the digestive tract.

Although the exact cause is unknown, an improperly functioning immune system mayresult in Crohn disease.

Typical symptoms include chronic diarrhea (which sometimes is bloody), crampyabdominal pain, fever, loss of appetite, and weight loss.

The diagnosis is based on a colonoscopy and imaging tests such as barium x-rays,computed tomography, or magnetic resonance imaging.

There is no cure for Crohn disease.

Treatment is aimed at relieving symptoms and reducing inflammation, but some peoplerequire surgery.

In the past few decades, Crohn disease has become more common worldwide. However, it ismost common among people of Northern European and Anglo-Saxon descent. It occurs aboutequally in both sexes, often runs in families, and seems to be more common among AshkenaziJews. Most people develop Crohn disease before age 30, usually between the ages of 14 and 24.

Most commonly, Crohn disease occurs in the last portion of the small intestine (ileum) and inthe large intestine, but it can occur in any part of the digestive tract, from the mouth to the anusand even in the skin around the anus. Crohn disease affects the small intestine alone (35% ofpeople), the large intestine alone (20% of people), or both the last portion of the small intestineand the large intestine (45% of people). The rectum is rarely affected, unlike in ulcerative colitis,in which the rectum is always involved. However, infections and other complications around theanus are not unusual. The disease may affect some segments of the intestinal tract while leavingnormal segments (called skip areas) between the affected areas. Where Crohn disease is active,the full thickness of the bowel is usually involved.

The cause of Crohn disease is not known for certain, but many researchers believe that adysfunction of the immune system causes the intestine to overreact to an environmental,dietary, or infectious agent. Certain people may have a hereditary predisposition to this immunesystem dysfunction. Cigarette smoking seems to contribute to both the development and the

hn Disease - Digestive Disorders - MSD Manual Consumer Version https://www.msdmanuals.com/home/digestive-disorders/inflammatory...

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periodic flare-ups (bouts or attacks) of Crohn disease. Oral contraceptives may increase the riskof Crohn disease.

The most common early symptoms of Crohn disease are chronic diarrhea (which sometimes isbloody when the large intestine is severely affected), crampy abdominal pain, fever, loss ofappetite, and weight loss. Symptoms may continue for days or weeks and may resolve withouttreatment. Complete and permanent recovery after a single attack is extremely rare. Crohndisease almost always flares up at irregular intervals throughout a person's life. Flare-ups can bemild or severe, brief or prolonged. Severe flare-ups can lead to intense, constant pain, fever, anddehydration. Why the symptoms come and go and what triggers new flare-ups or determinestheir severity is not known. Recurrent inflammation tends to appear in the same area of theintestine, but it may spread to adjacent areas after a diseased segment has been removedsurgically.

In children, abdominal pain and diarrhea often are not the main symptoms and may not appearat all. Instead, the main symptoms may be slow growth, joint inflammation, fever, or weaknessand fatigue resulting from anemia.

Complications

Common complications of inflammation include

Intestinal blockage (obstruction)

Abscesses (pus-filled pockets of infection) in the abdomen

Fistulas (abnormal connecting channels between the intestine and skin or other organs)

Anal fissures (tears in the skin of the anus), abscesses, and fistulas

Scarring due to chronic inflammation can cause intestinal blockage. Deep ulcers that penetratethrough the bowel wall can create abscesses or open fistulas. Fistulas may connect two differentparts of the intestine. Fistulas also may connect the intestine and bladder or the intestine andthe skin surface, especially around the anus. Although fistulas from the small intestine arecommon, wide-open holes (perforations) are rare. Fissures in the skin of the anus are common.

When the large intestine is affected extensively by Crohn disease, rectal bleeding commonlyoccurs. After many years, the risk of colon cancer (cancer of the large intestine) is greatlyincreased. About one third of people who develop Crohn disease have problems around theanus, especially fistulas and fissures in the lining of the mucus membrane of the anus.

Crohn disease may lead to complications in other parts of the body. These complications includegallstones, inadequate absorption of nutrients, urinary tract infections, kidney stones, anddeposits of the protein amyloid in several organs (amyloidosis).

When Crohn disease causes a flare-up of gastrointestinal symptoms, the person may also haveinflammation of the joints (arthritis), inflammation of the whites of the eyes (episcleritis),mouth sores (aphthous stomatitis), inflamed skin nodules on the arms and legs (erythemanodosum), and blue-red skin sores containing pus (pyoderma gangrenosum). Even when Crohndisease is not causing a flare-up of gastrointestinal symptoms, the person still may have


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inflammation of the spine (ankylosing spondylitis), inflammation of the pelvic joints(sacroiliitis), inflammation inside the eye (uveitis), or inflammation of the bile ducts (primarysclerosing cholangitis) entirely without relation to the bowel disease.

A doctor may suspect Crohn disease in a person with recurring crampy abdominal pain anddiarrhea, particularly if the person has a family history of Crohn disease or a history of problemsaround the anus. Other clues to the diagnosis may include inflammation in the joints, eyes, orskin or, in a child, stunted growth. The doctor may feel a lump or fullness in the lower part of theabdomen, most often on the right side.

No laboratory test specifically identifies Crohn disease, but blood tests may show anemia,abnormally high numbers of white blood cells, low levels of the protein albumin, and otherindications of inflammation such as an elevated erythrocyte sedimentation rate or level ofC-reactive protein.

People who have severe abdominal pain and tenderness have a computed tomography (CT) scanof their abdomen. CT may show a blockage, abscesses or fistulas, and other possible causes ofinflammation of the abdomen (such as appendicitis).

People who have less severe inflammation or who have had symptoms that recur over a period oftime have CT or magnetic resonance enterography, or plain x-rays are taken after barium isswallowed or given by enema. Another way in which the small intestine can be evaluated is with

wireless capsule endoscopy (seeVideo Capsule Endoscopy).

People who have little pain and mostly diarrhea undergo a colonoscopy (an examination of thelarge intestine with a flexible viewing tube) and a biopsy (removal of a tissue specimen formicroscopic examination). If Crohn disease is limited to the small intestine, colonoscopy will notdetect the disease unless the colonoscope is advanced all the way through the colon into the lastpart of the small intestine where the inflammation most often resides.

Crohn disease has no known cure and is characterized by intermittent flare-ups of symptoms.Flare-ups may be mild or severe, few or frequent.

Crohn disease usually does not shorten a person's life. However, some people die of cancer of thedigestive tract, which may develop more frequently than normally expected in long-standingCrohn disease.

Many treatments help reduce inflammation and relieve symptoms.

Antidiarrheal drugs


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These drugs, which may relieve cramps and diarrhea (seeAgents Used to Prevent or TreatConstipation), include drugs that have anticholinergic effects (drugs that block certain pathwaysof the nervous systemseeAnticholinergic: What Does It Mean?) such as diphenoxylate,loperamide, deodorized opium tincture, and codeine. They are taken by mouthpreferably

before meals. Taking methylcellulose or psyllium preparations sometimes helps prevent analirritation by making the stool firmer.

Anti-inflammatory drugs

Sulfasalazine and related drugs such as mesalamine, olsalazine, and balsalazide reduceinflammation. These drugs can suppress symptoms when they occur and reduce inflammation,especially in the large intestine. Typically these drugs are taken by mouth. Mesalamine is alsoavailable as a suppository or enema. Mesalamine may be effective in preventing recurrences.These drugs do not work as well for relieving severe flare-ups.

Corticosteroids such as prednisone, which is given by mouth, may dramatically reduce fever anddiarrhea, relieve abdominal pain and tenderness, and improve appetite and sense of well-being.

However, long-term corticosteroid therapy invariably results in side effects (see Corticosteroids:Uses and Side Effects). Usually, high doses are taken initially to relieve major inflammation andsymptoms. The dose is then reduced and the drug is discontinued as soon as possible. Anothercorticosteroid called budesonide has fewer side effects than prednisone, but it may not be quiteas rapidly effective and usually does not prevent relapses beyond 6 months.

As with corticosteroids taken by mouth, the dose of corticosteroids taken in enema or foam form(such as hydrocortisone) is reduced and gradually stopped.

If the disease becomes severe, the person is hospitalized and corticosteroids are given by vein(intravenously). Initially, the person is given nothing by mouth, and intravenous fluids are givento restore and maintain body fluids (hydration). People with heavy rectal bleeding may require

blood transfusions. People who have more chronic anemia may require iron supplements bymouth or intravenously.

Immunomodulating drugs

Drugs such as azathioprine and mercaptopurine, which modify the actions of the immunesystem, are effective for people with Crohn disease who do not respond to other drugs and areespecially effective for maintaining long periods of remission (periods of no symptoms). They

significantly improve the person's overall condition, decrease the need for corticosteroids, andoften heal fistulas. However, these drugs may not produce clinical benefits for 1 to 3 months andmay have potentially serious side effects. Therefore, a doctor closely monitors the person forallergy, a suppression of bone marrow, inflammation of the pancreas (pancreatitis), a low white

blood cell count, and sometimes liver problems. Blood tests that detect variations in one of theenzymes that metabolize azathioprine and mercaptopurine and that directly measure metabolitelevels may sometimes help the doctor ensure safe and effective drug dosages.

Methotrexate, given by injection or by mouth once a week, often benefits people who do notrespond to or who cannot tolerate corticosteroids, azathioprine, or mercaptopurine.

Cyclosporine is given by injection in high doses. This drug may help heal fistulas caused byCrohn disease but it cannot safely be used long term.

Infliximab,which is derived from monoclonal antibodies to tumor necrosis factor, is another


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modifier of the immune system's actions. Infliximab is given as a series of infusions. This drugcan be given to treat moderate to severe Crohn disease that has not responded to other drugs, totreat people with fistulas, and to maintain response when the disease is difficult to control.However, because the benefits of each infusion of infliximab are short-lived, other treatmentsare needed between infusions. Such treatments may include other immunomodulating drugssuch as azathioprine, mercaptopurine, or methotrexate. Because infliximab is a relatively newdrug, its long-term benefit and all of its side effects are not yet known, but it may worsen an

existing uncontrolled bacterial infection, may reactivate tuberculosis, and may increase the riskof some types of cancer. Some people have reactions such as fever, chills, nausea, headache,itching, or rash during the infusion.

Adalimumab is a drug related to infliximab and also focuses on regulating the immunesystem. Adalimumab is given as a series of injections. Adalimumab is particularly helpful forpeople who cannot tolerate or who no longer respond to infliximab. People may have pain anditching at the injection site.

Certolizumab is given as monthly injections. This drug works in a similar way as and causesside effects similar to those of infliximab and adalimumab.

Drug Some Side Effects Comments

Aminosalicylates

Sulfasalazine

Common: Nausea, headache,dizziness, fatigue, fever, rash, and, inmen, reversible infertility

Uncommon: Inflammation of the liver(hepatitis), pancreas (pancreatitis), orlung (pneumonitis) and hemolyticanemia

Abdominal pain, dizziness, andfatigue are related to dose.

Hepatitis and pancreatitis areunrelated to dose.

Balsalazide

Mesalamine

Olsalazine

Common: Fever and rash

Uncommon: Pancreatitis,inflammation of the pericardium(pericarditis), and pneumonitis

For olsalazine: Watery diarrhea

Most side effects seen withsulfasalazine may occur with anyof the other aminosalicylates butmuch less frequently.

Corticosteroids

PrednisoneDiabetes mellitus, high bloodpressure, cataracts, osteoporosis(decreased bone density), thinning of

Diabetes and high blood pressureare more likely to occur in people

who have other risk factors.


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skin, mental problems, acutepsychosis, mood swings, infections,acne, excessive body hair (hirsutism),menstrual irregularities, gastritis, and

peptic ulcer disease

BudesonideDiabetes mellitus, high bloodpressure, cataracts, and osteoporosis

Budesonide causes the same sideeffects as prednisone but to alesser degree.

Immunomodulators

Azathioprine

Mercaptopurine

Anorexia, nausea, vomiting, infection,cancer, allergic reactions, pancreatitis,low white blood cell count, bonemarrow suppression, and liverdysfunction

Side effects that are usually dosedependent include bone marrowsuppression and liverdysfunction.

Interval blood monitoring isrequired.

Cyclosporine

High blood pressure, nausea,

vomiting, diarrhea, kidney failure,tremors, infections, seizures,neuropathy, and development oflymphomas (cancers of the lymphaticsystem)

This drug is mainly for peoplewith fistulas.

Side effects become more likelywith long-term use.

Methotrexate

Nausea, vomiting, abdominal distress,headache, rash, soreness of the mouth,

fatigue, scarring of the liver(cirrhosis), low white blood cell count,and infections

Liver toxicity is likely dosedependent.

Methotrexate also causesabortion and birth defects duringpregnancy so it is not prescribedfor pregnant women or women

who may become pregnant.

Tacrolimus Similar to cyclosporineThis drug is closely related tocyclosporine and shares anumber of its side effects.

InfliximabInfusion reactions, infections, cancer,abdominal pain, liver dysfunction, andlow white blood cell count

Infusion reactions are potentiallyimmediate side effects that occurduring the infusion (such as


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fever, chills, nausea, headache,itching, rash, hives, decreased

blood pressure, or difficultybreathing).

People should be screened fortuberculosis before initiatingtreatment.

AdalimumabPain or itching at the injection site,headache, infections, cancer, andhypersensitivity reactions

Side effects are similar toinfliximab except adalimumabdoes not cause infusionreactions.

Hypersensitivity reactions areside effects that occur at theinjection site and include pain,rash, itching, and hives.

Certolizumab Similar to infliximab and adalimumab

Certolizumab works in a similarway as and causes side effectssimilar to those of infliximab andadalimumab.

Some doctors prefer this drugover infliximab and adalimumabfor pregnant and nursing

women.

Broad-spectrum antibiotics and probiotics

Antibiotics that are effective against many types of bacteria are often prescribed. The antibiotic

metronidazole is the most common choice for the treatment of abscesses and fistulas around theanus. Metronidazole may also help relieve the noninfectious symptoms of Crohn disease, such asdiarrhea and abdominal cramps. However, when used for a long time, metronidazole candamage nerves, resulting in a pins-and-needles feeling in the arms and legs. This side effectusually disappears when the drug is stopped, but relapses of Crohn disease after discontinuingmetronidazole are common. Some other antibiotics, such as ciprofloxacin or levofloxacin, may

be used in place of or in combination with metronidazole. Rifaximin, a nonabsorbable antibiotic,is also sometimes used in treating active Crohn disease.

Some bacteria are naturally found in the body and promote the growth of good bacteria

(probiotics). The daily use of probiotics, such as lactobacillus (typically present in yogurt) maybe effective in preventing pouchitis (see Inflammatory Bowel Diseases (IBD):Surgery).

Dietary regimens


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Defined-formula liquid diets, in which each nutritional component is precisely measured, mayimprove the condition of an intestinal obstruction or fistula at least for a short time. Nutritionaltherapy also may help children grow more than they might otherwise, especially when given atnighttime by tube feeding. These diets may be tried before or in addition to surgery.Occasionally, concentrated nutrients are given intravenously to compensate for the poorabsorption of nutrients that is typical of Crohn disease.

Surgery

Most people with Crohn disease require surgery at some point during their illness. Surgery isneeded when the intestine is obstructed or when abscesses or fistulas do not heal. An operationto remove diseased sections of the intestine may relieve symptoms indefinitely, but it does notcure the disease. Crohn disease tends to recur where the remaining intestine is rejoined,although several drug therapies initiated after surgery reduce this tendency. A second operationis ultimately needed in nearly half of the people. Consequently, surgery is performed only ifspecific complications or the failure of drug therapy makes it necessary. Still, most people whohave undergone surgery consider their quality of life to be better than it was before the

operation.

Because smoking increases the risk of recurrence, especially in women, doctors encouragepeople to quit smoking.

General management

Cramps and diarrhea may be relieved by taking loperamide or drugs that stop spasms in theabdomen (ideally before meals). Methylcellulose or psyllium preparations sometimes helpprevent anal irritation by making the stool firmer.

Severity of symptoms

For people who have mild to moderate symptoms, mesalamine is typically the first drug ofchoice. Some doctors give antibiotics instead of mesalamine or give antibiotics to people who arenot helped by mesalamine.

For people who have moderate to severe symptoms, corticosteroids (such as prednisone orbudesonide) are given by mouth or vein. People who are not helped by corticosteroids are givenother drugs such as azathioprine, mercaptopurine, or methotrexate. If people have anobstruction, doctors do nasogastric suction and give fluids by vein. In nasogastric suction, a tubeis passed through the nose into the stomach or small intestine, and suction is applied to the tubeto relieve abdominal swelling (distention).

For people whose symptoms developed suddenly or who have an abscess, fluids and antibioticsare given by vein in a hospital. Doctors drain the abscess surgically or by inserting a needleunder the skin and drawing out the fluid. Doctors give corticosteroids by vein to people whohave no infection or have an infection that is being controlled. Surgery is usually needed ifpeople are not helped by corticosteroids and antibiotics within 5 to 7 days.

Fistulas

People with fistulas are given metronidazole and ciprofloxacin. If these drugs do not help peoplein 3 to 4 weeks, doctors may give azathioprine or mercaptopurine and possibly infliximab,


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adalimumab, or certolizumab. Cyclosporine is an alternative, but fistulas often recur aftertreatment. People typically need definitive surgery to prevent the fistulas from recurring.

Maintenance regimens

To keep symptoms from returning (that is, to maintain remission), people must continue to takea regimen of mesalamine or corticosteroids or a combination of azathioprine, mercaptopurine,methotrexate, or infliximab or adalimumab or certolizumab. To maintain remission, the dosesfor most people will need to be increased or the intervals between regimens will need to beshortened within a year. During remission, doctors monitor people's symptoms and do bloodtests. X-rays are taken or a colonoscopy is done in people who have had Crohn disease for 7 or 8

years.


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