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Crohn's Disease Expanded Version

Crohn's Disease Expanded Version | ASCRS


Crohn's disease is a chronic inflammatory disease of unknown origin potentially affecting all parts of the gastrointestinal tract.   While medical management of the disease is the first choice, surgery may be indicated for specific reasons.  This information was prepared to help patients understand Crohn's, specifically the symptoms, evaluation and treatment options. This document may also be useful to the friends, families, and caregivers of patients dealing with Crohn's disease.

Crohn's disease most commonly affects older adolescents and adults.  It is extremely important to make an accurate diagnosis because Crohn's disease is but one of several inflammatory bowel diseases. Crohn's patients can have the same symptoms as those with other types of inflammatory bowel diseases such as ulcerative colitis.

In the following sections, we will describe the symptoms and diagnosis of Crohn's disease, outline the medical and surgical management of the disease, and identify techniques to minimize recurrence.   Successful treatment of Crohn's disease not only relieves symptoms, but often improves the quality of life for these patients.


Crohn’s disease was first defined in 1932 by Dr. Burrill B. Crohn and his colleagues working in New York City. Crohn’s patients have a life-long inflammation of the gastrointestinal tract that always involves the innermost inner lining of the gastrointestinal wall, known as the mucosa, though it can extend to the deeper layers of the wall.  The most common area of involvement is the point where the small bowel joins the large bowel.  However, Crohn's disease can occur at any point in the intestinal tract from the mouth to the anus, and can affect one or many areas.   There is no way to predict who will develop this disease or when the disease may appear.  It is a chronic life-long condition that can appear at any time, can go into remission without explanation, and can recur without apparent cause.   Unlike ulcerative colitis, there is no cure for Crohn's disease.   However, medical and surgical management of Crohn’s disease often provide patients with long periods of clinical remission.

Figure 1.  Diagram showing Crohn’s disease affecting the last part of the small bowel (ileum) and/or the large bowel (colon)


Crohn’s disease can affect anyone at any age, but the majority of patients develop symptoms during adolescence and young adulthood - between ages 15 and 35.  Crohn’s disease most often appears in the third decade of life and there has been an observed second peak in the sixth or seventh decade.  Both men and women are affected equally by this disease   A family history of Crohn's disease or inflammatory bowel disease slightly increases the risk of developing Crohn's. Smokers are at increased risk for developing the disease.


The exact cause of the disease is not known.  Current research is focused on abnormalities in the body's immune system and on bacterial infection. At this time, it seems most likely that Crohn’s disease is a form of autoimmune disease, where the patient’s own immune system attacks the intestinal tract, causing inflammation. This assumption is supported by evidence that symptoms are relieved when medications are used that suppress the immune system. Crohn’s is not contagious.  


Most commonly, Crohn’s disease appears as abdominal disease (affecting the small intestine or colon), as anorectal disease (affecting the anus and/or rectum), or as both.  Onset and symptoms vary widely from patient to patient.  The abdominal symptoms may include intestinal cramping, pain, persistent diarrhea or constipation, bleeding with bowel movements, fever, fatigue, and weight loss.  Not all the symptoms will appear in every patient.  Occasionally, the onset of Crohn's is sudden and severe; the patient quickly becomes very sick, and surgery is needed immediately.

Some Crohn’s patients develop a fistula, which is an abnormal passageway between the bowel and an organ or skin surface.  Fistulas can also form between loops of bowel, between bowel and bladder, between bowel and vagina, or between bowel and skin.  The anorectal symptoms include anal pain, and/or drainage from the perianal area..  These symptoms may also be caused by a non-healing or recurring perianal abscesses (pockets of infection) or anal fissures (painful clefts or grooves). 


The initial work-up of the patient includes taking a thorough medical history and physical examination followed by laboratory testing, examination of the inside of the bowel using instruments with flexible lighted cameras, and x-ray studies.  Your physician will inquire about a history of abdominal pain, nausea, vomiting, diarrhea or bleeding. Family history will be evaluated with attention to inflammatory bowel disease (Crohn’s disease and ulcerative colitis) as well as to whether or not there is a history of colorectal cancer or polyps. 

The laboratory tests may include basic blood tests, tests for C-reactive protein (measures general state of inflammation in the body), and screening tests, such as Prometheus.  The Prometheus test can help the physician to determine if you have inflammatory bowel disease, and if you do, whether it is more likely Crohn’s disease or ulcerative colitis. 

In addition to the blood work, a physical examination of the inside of the bowel is usually required, because this is the most accurate way to determine the extent of the disease.  The most common of these examinations is a colonoscopy. It is a procedure used to evaluate the inner lining of the colon and rectum as well as the lowest portion of the small intestine.  A colonoscope is a long, thin, tube-like flexible instrument, placed through the anus that provides magnified views of a patient’s large intestine (colon and rectum).  The colonoscope is commonly used to detect a variety of colon and rectal problems as well as to remove colon polyps and to screen for colon cancer.  The procedure is frequently performed in an outpatient setting with minimal discomfort and inconvenience.

Occasionally, the doctor will insert an endoscope through the mouth to look at the esophagus, the stomach, and the first portion of the small bowel.  Both of these examinations allow your doctor to directly visualize the innermost lining of the bowel (mucosa), take tissue for diagnosis, and, if indicated, to dilate scarred areas to permit easier passage of bowel contents and relieve symptoms of obstruction.

The finding of inflamed mucosa, stricture, or the opening of a fistula tract will help confirm the diagnosis of Crohn's and will help determine the extent of bowel involvement.  These findings will be used to determine a surgical plan if surgery is being considered.

Figure 2.  Figure showing the narrow luminal opening due to thickening of small bowel wall from Crohn’s disease

Radiographic studies may include a CT scan of the abdomen and pelvis to evaluate for inflammation or narrowing of the bowel, intrabdominal abscess (pocket of infection), or fistula connection between bowel and other structures.  Usually, this study requires the patient to drink a solution containing contrast material so that these abnormalities can be most clearly visualized.  To differentiate a chronic versus recent inflammation, your physician may sometimes order additional tests to show the inflammation and affected areas in greater detail.  A non-radiographic test may be used when there is concern for additional radiation exposure in a patient who has a history of multiple past radiographic tests. 


Treatment for Crohn’s disease is broadly categorized as medical or surgical in nature. It is important to note that there is currently no identified cure for Crohn’s disease. Medical management is aimed at achieving and maintaining a non-inflamed state and attempting to prevent recurrent disease. Surgical therapy is indicated for managing the complications of Crohn’s disease (obstruction, fistula, bleeding, etc).  Surgical removal of the segment(s) of intestine involved with Crohn’s does not cure the disease.  Removal addresses the immediate problem, but the disease often returns in areas previously not involved, often just upstream to the area where two previously healthy pieces of intestine are joined.


Once the diagnosis is made, medical management is always the first choice for treatment unless, as mentioned above, the patient's condition requires emergency operation.  In medical management, several treatment plans are available for initial therapy, for maintenance therapy, and to prevent recurrence. These medical treatments are often managed by the patient's gastroenterologist (a physician who specializes in the non-operative management of diseases of the intestine).  The most commonly used medication for acute flares of the disease is a corticosteroid, such as prednisone or methylprednisolone, combined with various anti-inflammatory agents and modifications in diet. Other immunosuppressive drugs are then often used to maintain remission.

Your doctor may also prescribe other medications depending on your history, age, general health, and specific disease.  If medical management is unable to relieve the pain, obstruction or fistula formation, surgery then becomes an option to improve the patient's health.


Surgery for Crohn's disease may either be done immediately or scheduled and done at a later date.  Emergency surgery is performed for patients who have developed conditions requiring treatment within a few hours of coming to the hospital.  Usually, these patients have either a bowel perforation (a hole in the bowel resulting in fecal matter leaking into the abdomen) or a complete obstruction (blockage) of the bowel.  Both of these conditions can threaten the patient's life.  Occasionally, a patient will require emergency surgery for a perianal abscess (pocket of infection by the anus) to drain the fluid collection in order to prevent further damage or spread of infection.

If surgery is indicated, the procedure will either be abdominal surgery or anorectal surgery.   Abdominal surgery addresses the entire abdomen, while anorectal surgery is restricted to the immediate anal area.  Abdominal surgery can be done as a traditional open surgical procedure or as a minimally invasive procedure using small incisions and cameras.  Your surgeon will decide between an open or minimally invasive procedure based on the extent of your disease and on which of these procedures would be safest with your history and general health.

Whether done as an open or minimally invasive procedure, abdominal surgery is performed to address a section of diseased bowel. Usually, the diseased area is scarred, has a hole in it, is too narrow for food to pass, or contains a fistula.  The two most common surgical procedures for Crohn's disease are removal of the end of the small bowel and the beginning of the large bowel and a procedure to relieve strictures. These are performed with the intent to preserve as much bowel as possible to improve the patient's prospect for more normal digestive function.

Figure 3.  Diagram showing the removal of portion of thickened small bowel with primary reconnection.           

Figure 4. Diagram showing stricturoplasty.  The narrowed portion of the bowel is opened and reconnected without resection to preserve the bowel length.

Because there is no cure for Crohn’s disease and recurrence is common, your surgeon will want to preserve as much intestine as possible with each surgery.   There is a high chance of recurrence depending on the severity of the disease.  Recurrence rates can be around 25% and 35% at 5 and 10 years, respectively.

Following removal of a portion of the bowel, it is not always possible or prudent to reconnect the remaining bowel into a continuous length, owing to remaining disease or shortening of the bowel.  When this is the case, your surgeon may elect to create an ostomy. An ostomy is a surgically created opening between an internal organ and the surface of the abdominal wall.  A circular incision is made in the abdominal wall and a piece of intestine is brought through the incision to lie partially outside the body wall. The part of the bowel that is seen on the abdomen surface is called a stoma.   The end of small bowel or the end of the large bowel that is sewn to the abdominal wall is also known as an ostomy.  Ostomies may be intended to be permanent or temporary, depending on the particular circumstances.

Besides the normal risks related to any surgery, a major risk of surgery on the bowel is that a leak will develop at the point where the remaining bowel has been reconnected following removal.  A leak may develop either soon after surgery or at a later time. This risk is further elevated by the use of steroids both before and after surgery, smoking, poor nutrition, and severe inflammation. Additionally, steroid use can result in poor wound-healing ability. Your surgeon will monitor you closely for complications following surgery so that if they occur, the complication can be addressed.

Anorectal surgery for Crohn’s disease is most commonly performed to drain an anorectal pocket of infection.  During the procedure, the infected cavity is opened and the fluid drained out.   In cases where the infection process is still active and fluid is still being formed, a fistula (connection to the diseased anus or rectum draining outside next to the anus) may be present. Your surgeon may place a piece of suture or thin rubber band like material as a loop through the fistula tract, commonly called a seton   Placing a seton promotes controlled drainage and helps avoid undrained pockets from reforming.  The seton will be left in place until medical management is able to keep the drainage under control (normally weeks), at which point the surgeon can consider removing it.  

Anorectal surgery is also performed to correct a fistula (an abnormal passageway between the bowel and nearby organs or between the bowel and skin).  In the setting of one or more significant anal fistulae, patients are occasionally given an ostomy to divert the fecal stream away from the anal fistula until medical management can become effective and the wound has completely healed.  The ostomy can often be reversed once the wound has healed, but this will depend upon the patient's overall general health and the progress of the Crohn's disease.


Your doctor will want re-establish care very quickly, after surgery.  At that follow-up appointment, your doctor will introduce a medication regime to control the disease and prevent recurrence.   

Patients with inflammatory bowel disease (Crohn’s disease or ulcerative colitis) are at increased risk for developing colon and rectal cancers.  In patients with longstanding colonic Crohn’s disease, the increased risk for developing colon or rectal cancer can be up to 20 fold.  The guidelines currently in use recommend that these patients have their first follow-up colonoscopy within eight to ten years after the onset of symptoms, followed by follow-up colonoscopy with multiple biopsies (tissue examination) throughout the colon and rectum.


Recurrence is most often seen in patients who continue to smoke.  It is also common in patients who stop their medications to treat their Crohn’s disease either because of their inability to afford the medication or their refusal to continue with the life-long treatment.  Crohn's disease is a chronic, life-long condition that requires continuous attention to control. 


  1. When do I need surgery?
  2. What are my options for surgery?
  3. What operative approach will be used (laparoscopy or open)?
  4. What is the likelihood of my needing a Stoma?
  5. What can I expect after surgery?
  6. When do I need repeat colonoscopy?
  7. What options do I have for anesthesia with an operative procedure?
  8. How do you plan to address my pain after surgery?
  9. What will happen if I don’t want any treatment?


Colon and rectal surgeons are experts in the surgical and non-surgical treatment of diseases of the colon, rectum, and anus.  They have completed advanced surgical training in the treatment of these diseases, as well as full general surgery training.  Board-certified colon and rectal surgeons complete residencies in general surgery and colon and rectal surgery, and pass intensive examinations conducted by the American Board of Surgery and the American Board of Colon and Rectal Surgery. They are well versed in the treatment of both benign and malignant diseases of the colon, rectum, and anus and are able to perform routine screening examinations and surgically treat conditions, if indicated to do so.


The American Society of Colon and Rectal Surgeons is dedicated to ensuring high-quality patient care by advancing the science, prevention and management of disorders and diseases of the colon, rectum and anus. These brochures are inclusive but not prescriptive. Their purpose is to provide information on diseases and processes, rather than dictate a specific form of treatment. They are intended for the use of all practitioners, health care workers and patients who desire information about the management of the conditions addressed. It should be recognized that these brochures should not be deemed inclusive of all proper methods of care or exclusive of methods of care reasonably directed to obtain the same results. The ultimate judgment regarding the propriety of any specific procedure must be made by the physician in light of all the circumstances presented by the individual patient. 


Bickston, S.J. and Bloomfeld, R. S.  Handbook of Inflammatory Bowel Disease. Lippincott Williams & Wilkins, Baltimore, MD; 2010

Strong, S.A. Chapter 30, “Crohn’s Disease: Surgical Management” . Chapter in Beck, D. E., Roberts, P.L., Saclarides, T.J., Senagore, A.J., Stamos, M. D., Wexner, S.D.. Eds. ASCRS Textbook of Colon and Rectal Surgery, 2nd Edition. Springer, New York, NY; 2011

ASCRS website, 2011 Core Subjects; Efron J “Crohn’s Disease”

Strong, S. A., Koltun, W. A., Hyman, N. H., Buie, W. D.; Standards Practice Task Force, American Society of Colon and Rectal Surgeons. Practice Parameters for the Surgical Management of Crohn’s Disease (Revised 2007). Dis Colon Rectum. 2007;50(11):1735-1746.


ACKNOWLEDGEMENT:  ASCRS thanks Sanda A. Tan, MD, PhD, for her assistance with the development of this educational brochure.