Distinguishing characteristics of CD and UC UC CD Feature Only colon (rarely “ backwash ileitis ” SB or colon Location Continuous, begins distally Skip lesions Anatomic distribution Involved in >90% Rectal spare Rectal involvement Universal Only 25% Gross bleeding Rare 75% Peri-anal disease No Yes Fistulization No 50-75% Granulomas
Endoscopic features of CD and UC UC CD Feature Continuous Discontinuous Mucosal involvement Rare Common Aphthous ulcers Abnormal Relatively normal Surrounding mucosa Rare Common Longitudinal ulcer No In severe cases Cobble stoning Common Uncommon Mucosal friability distorted Normal Vascular pattern
Pathologic features of CD and UC UC CD Feature Uncommon Yes Transmural inflammation No 50-75% Granulomas Rare Common Fissures No Common Fibrosis Uncommon Common Submucosal inflammation
Radiologic features of CD and UC UC CD Feature Collar button ulcers Nodularity granularity cobble stoning string sign of SB
Comparison of Features in Ulcerative Colitis and Crohn's Disease Crohn's Disease Ulcerative Colitis Feature Transmural Mucosal Depth of inflammation Skip areas Contiguous Pattern of disease Mouth to anus Colorectum Location Less common Usual Rectal involvement Common Backwash ileitis (15%–20% of patients ) Ileal disease Common Rare Fistulas Common Rare Perianal disease 10%–30% of patients Unlikely Granulomas Less common Usual Overt bleeding More common Unlikely Malnutrition Colorectal cancer, small bowel cancer (depending on disease location ) Colorectal cancer, cholangiocarcinoma (if primary sclerosing cholangitis is present ) Cancer risk Harmful Protective Tobacco use
CD may affect any segment of the GIT, is often discontinuous & may cause CD commonly present with abdominal pain, diarrhea& weight loss.
Disease involving the small intestine often causes nonbloody diarrhea, whereas hematochezia is more likely when the colon is involved.
Diarrhea may be due to bacterial overgrowth, bile acid malabsorption, or steatorrhea, depending on the extent of disease, the presence of complications (e.g., strictures)& whether or not intestinal resection was performed.
CD may also present with bowel obstruction due to inflammation or fibrosis.
Those with fistulizing disease may have pneumaturia, fecaluria, & recurrent or &vaginal drainage of feces (due to enterovaginal fistulas), or seepage of bowel contents through the skin (caused by enterocutaneous fistulas).
Primary sclerosing cholangitis occurs in 5% of patients with UC&to a lesser extent CD.
Patients may present incidentally with jaundice, portal hypertension, or lab findings indicative of cholestasis.
Patients with UC&primary sclerosing cholangitis are at an even higher risk of developing colon cancer than are those with ulcerative colitis alone.
Metabolic bone disease is common , especially those with CD,can occur independent of corticosteroid use& is associated with an increased risk of fractures.
Patients with prolonged IBD, malabsorption, a history of using corticosteroids for >3 months, cigarette smoking, older age, history of fractures, or a family history of osteoporosis should be evaluated for the presence of metabolic bone disease.
Kidney stones / gallstones are other extraintestinal manifestations of inflammatory bowel disease.
Cancer: Patients with either UC or CD have an increased risk of intestinal dysplasia & CRC that is related to the duration, extent& severity of the inflammation,so those with extensive/longstanding disease should undergo regular colonoscopic examinations with mucosal biopsies to detect these complications.
Standard Diagnostic Evaluation for Suspected IBD: Colonoscopy with intubation of the terminal ileum& biopsies of the involved mucosa Stool analysis for ova / parasites & Clostridium difficile toxin plus stool culture Barium radiographs of small bowel, CT enterography&/or capsule endoscopy if Crohn's disease is suspected Plain abd radiographs if bowel obstruction, toxic megacolon, or perforation is suspected Abdominopelvic CT scan if abscess or fistula is suspected
Topical therapy is appropriate for distal disease.
Options include cortisone foam & mesalamine or corticosteroid suppositories for proctitis & hydrocortisone or mesalamine enemas for left-sided colitis.
Oral 5-aminosalicylates, including sulfasalazine, mesalamine, balsalazide& olsalazine, are appropriate for distal disease that does not respond to topical therapy or for mild to moderate pancolitis.
Oral prednisone is used when symptoms do not respond to 5-aminosalicylates.
Because prednisone & other corticosteroids have many acute / chronic toxic effects that are dose-/ duration-dependent, the lowest effective dose should be given for the shortest time.
Azathioprine (AZA) or 6-mercaptopurine (6-MP) may be used for patients who have incomplete disease remission while on corticosteroids,but both have delayed onset of action,so concomitant use of either AZA or 6-MP together with a 3- to 4-month course of prednisone is often necessary.
IV corticosteroids (equi to 40-60 mg of methylprednisolone) are indicated for treatment of severe ulcerative colitis unless the patient has fulminant disease or a complication that requires urgent surgery.
IV corticosteroids should only be used for 7 - 10 days.
If the patient does not respond, surgery, infliximab, or cyclosporine should be considered.
Although cyclosporine is generally effective, its use is limited because of its potential toxic effects.
Narcotics / anticholinergic agents should be avoided in order to reduce the risk of precipitating megacolon.
Infliximab is effective for treating UC that is refractory to other therapies & favored by some because of a perception of fewer side effects with infliximab than with cyclosporine.
Patients with mild distal disease may not need maintenance therapy.
Patients with more severe disease should most likely continue treatment to prevent relapse.
The same medication used to achieve remission can often be given successfully for maintenanceas oral or topical 5-aminosalicylate.
Because 5-aminosalicylates have dose-dependent efficacy, tapering the dose during maintenance may increase the chance of relapse.
Topical & systemic corticosteroids are neither effective nor safe for use as maintenance therapy.
Patients whose acute symptoms responded to oral corticosteroids may receive maintenance 5-aminosalicylates for milder disease or AZA/6-MP for more severe ulcerative colitis.
AZA/6-MP may also be used for patients who did not respond to a 5-aminosalicylate alone.
If a 5-aminosalicylate is used for maintenance therapy, corticosteroids should be tapered over several weeks,but disease flares during corticosteroid taper indicate the need for AZA/6-MP followed by slow tapering of corticosteroids over a 3- to 4-month period.
When remission is achieved with IV corticosteroids, changing to oral prednisone & AZA/6-MP is appropriate.
Treatment for Crohn's disease is similar to that for ulcerative colitis with the following exceptions:
1) smokers should be encouraged to stop;
2) 5-aminosalicylates are less effective for treating CD
3) metronidazole is an option for induction therapy.
Drugs targeting the colon, as sulfasalazine, balsalazide, olsalazine, are ineffective for treating small-bowel CD. Instead, mesalamine may be used for mild disease of the small bowel (Asacol® for ileal delivery and Pentasa® for more proximal delivery
Patients who do not respond to this regimen are treated as for those with moderate disease.
Patients with moderate disease (presence of fever, weight loss, abdominal tenderness without rebound, nausea or vomiting without obstruction, significant anemia) require corticosteroids.
Budesonide is an option for disease limited to the distal ileum and right colon because this corticosteroid is designed to deliver drug to this area of the bowel& has limited toxicity as a result of extensive metabolism in the liver.
Prednisone is used for more diffuse disease.
Patients who have an incomplete response or become corticosteroid-dependent should be given AZA/6-MP or methotrexate, especially if surgery is contraindicated.
Patients with severe Crohn's disease (presence of high fever, persistent vomiting, obstruction, abdominal tenderness with rebound, cachexia) in whom infection has been excluded require hospitalization and the same treatment used for those with severe ulcerative colitis. Infliximab should be considered when there is no response to IV corticosteroids.