Crohn’s disease (more appropriately designated as Crohn disease) is an inflammatory disease of the intestine which may effect any part of the GI tract. It is one of the 2 types of distinct inflammatory bowel disease (IBD).

Background: Crohn’s disease is a chronic disease of the intestine. The intestine becomes inflamed which leads to pain, loose stools, and bleeding. Over time, complications such as scar tissue (stricture) or rupture (intestinal perforation) may develop.  Unlike it’s counterpart, ulcerative colitis (which is limited to the colon), Crohn’s disease may affect any part of the GI tract.  The terminal ileum (junction of the large and small intestine)  is most commonly affected, while the rectum is often spared. Crohn’s disease may have a wide variety of different ways of showing up. This can make the initial diagnosis more difficult in some people.

Prevalence in the United States is about 7 cases per 100,000 people. While it is more common in Caucasians and Ashkenazi (Eastern European) Jews, anyone may have it. Doctors sometimes refer to the ages at which Crohn’s disease develops as “bimodal.” It is common to first develop either during the teen’s-20’s or around the ages of 50’s-70’s. Males and females are at equal risk. Crohn’s disease, however, is 3x more likely in smokers, and people with a first degree relative with Crohn’s are at a 4-20x increased risk.

Presenting problem:  The most common initial symptoms are crampy abdominal pain, chronic diarrhea, low-grade fever, weight loss, and/or fatigue.  Diarrhea is usually non-bloody and intermittent.  Abdominal pain may be in the right lower part of the abdomen, around the belly button (umbilicus).  The pain is often relieved by defecation.  If there is colon involvement, pain can be diffuse and blood may be present in the stool (bloody stools).  Some patients do not present to a physician until they have a bowel obstruction (intestinal blockage).  Other symptoms include intestinal spasm, loud intestinal noises, cramping, bloating after meals.   Associated problems may include chronic constipation or even complete inability to have a bowel movement (obstipation).  Children may present with growth failure or delayed puberty due to malabsorption

1. The exact cause remains unknown
2. Genetics, environmental, vascular, immunologic, and dietary causes have all been suggested in development of Crohn’s disease
3. Researchers believe several genes may contribute to Crohn’s disease
4. Specifically, mutations in the CARD15/NOD2 gene have shown increased susceptibility
5. TNF-a and interleukins have also been implicated in disease development
6. Crohn’s results in a T-helper Type 1 immune response → increased IL-12, TNF-a, and IFN-g
7. In particular, TNF-a has been shown to have a critical role in the high degree of inflammation in Crohn’s
8. Crohn’s patients demonstrate increased TNF levels in stool, mucosa, and blood
9. Environmental factors may contribute: industrialized country, smoking
10. Diet factors

Pathophysiology (how the disease gets worse)

1. Lesions start as focal inflammation around crypts and result in superficial mucosa ulceration
2. With progression, inflammation spreads to deep layers and begins noncaseating granuloma and lymphoid aggregate formation
3. Superficial ulcers will become deep serpiginous
4. Linear ulcers and transverse fissures will create a cobblestone appearance
5. Healthy tissue separates areas of disease (skip lesions)
6. Transmural inflammation results in narrowing of the bowel lumen and thickening of the wall

Extra-intestinal Manifestations (Crohn’s problems other than intestine)

1. Aphthous ulcers (mouth sores)
2. Uveitis (eye inflammation)
3. Episcleritis (eye inflammation)
4. Seronegative spondyloarthropathy (joint pain)
5. Ankylosing spondylitis, sacroiliitis (joint and back pain)
6. Erythema nodosum (skin lumps)
7. Pyoderma gangrenosum (skin problem)
8. Variable liver involvement: elevated liver enzymes, benign pericholangitis, sclerosing cholangitis, autoimmune hepatitis
9. Clubbing of the fingers
10. Osteoporosis
11. Amyloid deposits in kidney

Labs abnormalities:

1. Anemia (low red blood cell counts)
2. Leukocytosis (elevated white blood cell counts)
3. Acute inflammatory markers (sed rates, CRP, etc.)
4. Signs of malabsorption (low albumin, other labs)
5. Serology (p-ANCA which is suggestive of UC), Prometheus IBD Serology 7
6. Stool samples (to exclude infection, to check for white cells, to look for blood)

Imaging options:

1. Colonoscopy with biopsy
2. Upper GI with small bowel follow-through
3. Barium enema
4. CT scanning for stricture, fistula, obstruction, appendicitis
5. Capsule endoscopy
6. MR Enterography

Treatment:

1. Treatment of children should always be done by a board certified pediatric gastroenterologist.
2. No cure for Crohn’s disease
3. Goal of treatment is to treat flare ups and maintain remission
4. Treatment options: medications, lifestyle changes, surgery
5. Acute treatment
6. Antibiotics (metronidazole, ciprofloxacin) to treat infection
7. Aminosalicylate (Mesalazine, Sulfasalazine) and corticosteroids (prednisone) to reduce inflammation
8. Immunosuppressive Agents: azathioprine, 6-mercaptopurine
9. Anti-TNF-a antibody: infliximab, adalimumab (Remicade, Humira)

Surgery:

1. Surgery reserved for patients with persistent symptoms despite high-dose steroids, complications, dysplasia (precancer), fistula, abscess, severe bleeding or obstruction
2. Crohn’s disease cannot be cured by surgery.  Surgery treats the complications of the disease.
3. Higher need for more surgery in patients who need surgery a first time.
4. Scar formation often contributes to stricture development
5. Studies have suggested, following an initial resection another procedure may be necessary in 5 years
6. Lower recurrence seen with total colectomy and ileostomy verses segmental procedures

Surgical Options:

1. Resection and anastomosis
2. Often requires ostomy to allow bowel to heal
3. Risk of fistula or stricture development
4. Strictureplasty: 1/2 of patients will require re-operation, most effective in jejunum and ileum. Preferable for patients with prior resection who are at risk for short bowel syndrome
5. Balloon dilation. Long term success has not been determined. Appears to be useful in delaying resection or strictureplasty. Risk of bowel tearing.
6. In children, surgical resection (rather than stricturoplasy) of ileocolic stricture often results in marked reduction in symptoms if the disease is limited to one area. Again, surgery does not cure the disease.

Potential Complications from Crohn’s Disease: (bolded entries often require surgery)

1. Obstruction (intestinal blockage)
2. Fistula (a track between the intestine and any other structure (skin, bladder, intestine, vagina, etc))
3. Malabsorption (inability to absorb nutrients)
4. Perianal disease (inflammation of the area around the anus)
5. Toxic megacolon (a massively stretched colon)
6. Perforation (rupture of the intestine)
7. Severe GI bleeding (blood in the stool which causes anemia).

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