What is Crohn’s disease?
Crohn's disease is a chronic inflammatory condition that may begin as localized inflammation in the bowel mucosa but can progress to inflammation involving the entire bowel wall. Although Crohn’s disease can involve any part of the gastrointestinal tract, it more commonly tends to be localized in the terminal part of the ileum and right colon. Up to 30% of patients also develop perianal Crohn’s disease, which can present as abscesses, fissures or fistulas around the anus and rectum. Over time, narrowings of the bowel called strictures, abnormal connections from the bowel to surrounding structures called fistulas, or abscesses may develop.
What causes Crohn's disease?
While the true cause of inflammatory bowel disease is yet to be determined, it’s thought to be the result of the interplay of genetics, immune system abnormalities and environment. We do know that there is a genetic predisposition: 20 percent of Crohn's patients have an affected first-degree relative. The incidence of Crohn's is highest in white males and females who live in temperate zones. North American and Western European Jews (Ashkenazi Jews) have the highest incidence. Although the peak age of onset is between 15 and 30 years of age, Crohn’s disease can occur at any age.
What are the symptoms of Crohn's disease?
Diarrhea, cramping abdominal pain and weight loss are the predominant symptoms. These complaints may be vague for the first few months or years. Other symptoms associated with Crohn's are fever, malnutrition, symptoms related to anemia and abdominal tenderness. In children, one of the earlier signs of Crohn’s disease is growth delay.
How is Crohn's disease diagnosed?
There is no single test that diagnoses Crohn’s disease. Your clinical history and physical examination may provide clues based on the presenting gastrointestinal symptoms, and physical exam findings such as a palpable abdominal pass, perianal skin tags, oral aphthous ulcers or characteristic skin lesions from conditions associated with Crohn’s disease. Laboratory testing to look for signs of anemia, malnutrition, inflammation or infection are also used to help with diagnosis and management of Crohn’s disease. Radiographic studies to closely evaluate the small bowel such as small bowel series, magnetic resonance or computed tomography enterography are also used to identify areas of inflammation, stricture, fistula or abscess. Endoscopy, with either an upper endoscopy, or more commonly, colonoscopy, is performed to evaluate the small bowel or colonic mucosa and obtain tissue.
Can this condition be prevented?
There is no testing currently available to predict who will be diagnosed with Crohn’s disease. Early detection with appropriate gastroenterology evaluation if symptoms suspicious of Crohn’s disease are present is the most important first step, particularly if there is a family history of inflammatory bowel disease.
What is the treatment for Crohn's disease?
While there is no cure for Crohn’s disease, the goals of therapy are first to obtain and then maintain remission. Remission in Crohn’s disease means an absence of symptoms and ideally healing of the inflamed affected mucosa. The treatment for Crohn's is based on the severity of the disease. For mild to moderate Crohn's, antibiotics and 5-aminosalycilates such as mesalamines have been used although the evidence supporting their efficacy in Crohn’s disease is somewhat mixed. Budesonide, an enteric coated steroid with low systemic bioavailability (which translates to fewer steroid-related side effects), may be an effective treatment for mild to moderate Crohn’s disease. For moderate to severe Crohn’s disease, treatment regimens include corticosteroids, immunomodulators and biologic agents.
Corticosteroids (prednisone), are used as an induction agent to obtain symptomatic control. They are not meant to be used as a maintenance therapy and should be initiated with concurrent plans to transition to a steroid-sparing regimen. Long-term use of corticosteroids is associated with increased risk of infection, osteoporosis, glaucoma/cataracts, diabetes and weight gain. Immunomodulators, such as 6-mercaptopurine (6MP), azathioprine or methotrexate have been used as a steroid-sparing regimen for Crohn’s disease for over 40 years. These alter the immune response by inhibiting the natural killer cell activity and suppressing T-cell function. Adverse reactions to these medications can include elevated liver enzymes, pancreatitis, bone marrow suppression, increased risk of lymphoma and non-melanoma skin cancers. These medications, while effective when used in the appropriate clinical setting, require routine laboratory monitoring and close follow-up with your Crohn’s disease specialist.
The biologic agents, which include infliximab (Remicade®), adalimumab (Humira®), and certolizumab pegol (Cimzia®), are also steroid sparing agents that can be used both for induction as well as maintenance of remission. These agents are available via infusion (infliximab) or injection (adalimumab and certolizumab pegol) and have demonstrated efficacy to improve clinical symptoms as well as heal mucosa. Adverse reactions to these biologic agents include injection or infusion reactions, infection (including hepatitis B, tuberculosis and opportunistic infections) and lymphoma. Patients with symptomatic congestive heart failure should not receive these medications.
Elemental diets have been effective for the pediatric Crohn's patients. They are composed of simple sugars and amino acids that do not require digestion. This type of diet alters the intestinal luminal contents and provides relief for the bowel while medical therapy is initiated. The efficacy of elemental diets among adult Crohn’s disease patients remains to be determined. Upon resumption of a normal diet, symptoms tend to recur. Total parenteral nutrition (TPN) may be used in severe Crohn's disease, particularly when severe malnutrition is present, to rest the bowel for a period of time either as a bridge to surgery or initiation of medical therapy.
Will I need to have surgery?
About 40 to 60 percent of patients with ileal Crohn's disease need surgery during the first 10 years of symptoms, most often at eight to 10 years. Factors that may influence surgical risk include stricturing or fistulizing disease behavior, young age at diagnosis, medically refractory disease and current smoking. Smoking increases the risk of developing the stricturing or fistulizing behaviors of Crohn’s disease, decreases the efficacy of available medications to treat Crohn’s disease and increases likelihood of needing additional surgeries at a shorter interval in the future. Patients who quit smoking have a marked decrease risk of surgery with up to a 70 percent reduction in need for future reoperation.
What surgery is performed?
Bowel resections (surgical removal of the affected part(s) of the small bowel colon) are the most commonly performed surgeries. If a short-segment stricture is present, sometimes a procedure called a stricturoplasty is performed which opens up the narrowed bowel without resection. For perianal disease, abscess drainage is often performed along with placement of a seton to allow for adequate drainage for healing without recurrent infection.
What is “short-bowel syndrome?”
This term refers to the malabsorptive state that occurs after removal of a substantial segment of small intestine. Depending on how much of the ileum and possibly the jejunum are affected, colonic pseudo-obstruction may occur.
What is the goal of treatment? Can this disease be cured?
The goal of medical therapy is to treat the active disease and to maintain remission. The treatment should successfully suppress active inflammatory disease medically and try to conserve bowel. Surgery should be reserved for managing complications of Crohn's, such as fistulae and abscesses, and for treating obstructions.
What lifestyle changes will I need to make?
Most patients who are managed with the current standard medical and surgical approaches report a good quality of life. The prognosis for long-term survival and an acceptable lifestyle are excellent. Patients with severely compromised small intestine function, young people with extensive disease or ostomies or patients who need long-term hyperalimentation can become severely depressed. The physician should be cognizant of this and treat the patient appropriately. Drug dependence could become a problem for the patient with severe Crohn's disease. A multidisciplinary approach to addressing Crohn’s disease involving your gastroenterologist, colorectal surgeon, psychologist/psychiatrist, primary care physician, registered dietitian, and for women, obstetrics-gynecology, is important to help manage disease burden from not only a gastrointestinal perspective but an emotional, mental and family-planning viewpoint.
Where can I go to find out more information on Crohn’s Disease or meet other people who have the same problem?
Patient support groups and health organizations are dedicated to providing information and educational materials to help improve overall patient management and satisfaction. There are also numerous support and advocacy groups for people who have had, or will have, intestinal diversions. The Internet hosts a number of these groups and organizations. Your physician can also make suggestions about local groups.