Inflammatory Bowel Diseases - Crohn's and UC

What % of CD pts eventually have some form of surgery ?

Approx. 80%

Most common extra-intestinal features with IBD ?

Arthritis

Differences in potential complications

Colorectal Ca risk higher in UC than CD

Cause of CD

Unknown - strong genetic susceptibility

Complications of CD

small bowel cancer (standard incidence ratio = 40) colorectal cancer (standard incidence ration = 2, i.e. less than the risk associated with ulcerative colitis) osteoporosis

Differences in extra-intenstinal manifestations

*impaired bile acid rebsorption increases the loss calcium in the bile. Calcium normally binds oxalate.

Mx to induce remission

1. Glucocorticoids (oral, topical or intravenous) are generally used to induce remission. Budesonide is an alternative in a subgroup of patients 2. Enteral feeding with an elemental diet may be used in addition to or instead of other measures to induce remission, particularly if there is concern regarding the side-effects of steroids (for example in young children). 3. 5-ASA drugs (e.g. mesalazine) are used second-line to glucocorticoids but are not as effective 4. azathioprine or mercaptopurine* may be used as an add-on medication to induce remission but is not used as monotherapy. Methotrexate is an alternative to azathioprine. 5. Infliximab is useful in refractory disease and fistulating Crohn's. Patients typically continue on azathioprine or methotrexate. metronidazole is often used for isolated peri-anal disease

Why are patients with Crohn's are prone to strictures, fistulas and adhesions ?

Because inflammation occurs in all layers, down to the serosa.

Small bowel barium enema picture in CD

Barium study is shown from a patient with worsening Crohn's disease. Long segment of narrowed terminal ileum in a 'string like' configuration in keeping with a long stricture segment. Termed 'Kantor's string sign'.

Investigations for CD

Bloods C-reactive protein correlates well with disease activity Endoscopy colonoscopy is the investigation of choice features suggest of Crohn's include deep ulcers, skip lesions Histology inflammation in all layers from mucosa to serosa goblet cells granulomas Small bowel enema high sensitivity and specificity for examination of the terminal ileum strictures: 'Kantor's string sign' proximal bowel dilation 'rose thorn' ulcers fistulae

Triggers for UC flare

Most ulcerative colitis flares occur without an identifiable trigger. However, a number of factors are often linked: - stress - medications (NSAIDs,antibiotics) - cessation of smoking

Most common site for UC ?

Rectum - always starts here and spreads proximally The peak incidence of ulcerative colitis is in people aged 15-25 years and in those aged 55-65 years.

What should be assessed before starting azathioprine or mercaptopurine ?

TPMT activity thiopurine methyltransferase

Where does Crohn's commonly affect ?

Terminal ileum and colon. May be seen anywhere from mouth to anus.

Surgical management of CD

The commonest disease pattern in Crohn's is stricturing terminal ileal disease and this often culminates in an ileocaecal resection. Other procedures performed include segmental small bowel resections and stricturoplasty. Colonic involvement in patients with Crohn's is not common and, where found, distribution is often segmental. The standard options of colonic surgery in Crohn's patients are generally; sub total colectomy, panproctocolectomy and staged sub total colectomy and proctectomy. Restorative procedures such as ileoanal pouch have no role in therapy. Crohn's disease is notorious for the developmental of intestinal fistulae; these may form between the rectum and skin (perianal) or the small bowel and skin. Fistulation between loops of bowel may also occur and result in bacterial overgrowth and malabsorption. Management of enterocutaneous fistulae involves controlling sepsis, optimising nutrition, imaging the disease and planning definitive surgical management.

Maintaining remission

as above, stopping smoking is a priority (remember: smoking makes Crohn's worse, but may help ulcerative colitis) 1. azathioprine or mercaptopurine is used first-line to maintain remission 2. Methotrexate is typically used second-line. 3. 5-ASA drugs (e.g. mesalazine) should be considered if a patient has had previous surgery

When does Crohn's typically present ?

late adolescence or early adulthood.

Barium enema findings for UC

loss of haustrations superficial ulceration, 'pseudopolyps' long standing disease: colon is narrow and short -'drainpipe colon' Barium enema from a patient with ulcerative colitis. The whole colon, without skips is affected by an irregular mucosa with loss of normal haustral markings.

Maintaining remission Following a mild-to-moderate ulcerative colitis flare - left-sided and extensive ulcerative colitis

low maintenance dose of an oral aminosalicylate

Other points on the Mx of UC

methotrexate is not recommended for the management of UC (in contrast to Crohn's disease) there is some evidence that probiotics may prevent relapse in patients with mild to moderate disease

Following a severe relapse or >=2 exacerbations in the past year

oral azathioprine or oral mercaptopurine

General points on Mx of Crohn's

patients should be strongly advised to stop smoking some studies suggest an increased risk of relapse secondary to NSAIDs and the combined oral contraceptive pill but the evidence is patchy

Inducing remission with severe colitis

should be treated in hospital intravenous steroids are usually given first-line intravenous ciclosporin may be used if steroid are contraindicated if after 72 hours there has been no improvement, consider adding intravenous ciclosporin to intravenous corticosteroids or consider surgery

Managment of mil-moderate colitis (includes flares) - proctosigmoiditis and left-sided ulcerative colitis

topical (rectal) aminosalicylate if remission is not achieved within 4 weeks, add a high-dose oral aminosalicylate OR switch to a high-dose oral aminosalicylate and a topical corticosteroid if remission still not achieved stop topical treatments and offer an oral aminosalicylate and an oral corticosteroid

Maintaining remission Following a mild-to-moderate ulcerative colitis flare - Proctitis and proctosigmoiditis

topical (rectal) aminosalicylate alone (daily or intermittent) or an oral aminosalicylate plus a topical (rectal) aminosalicylate (daily or intermittent) or an oral aminosalicylate by itself: this may not be effective as the other two options

Managment of mil-moderate colitis (includes flares) - extensive disease

topical (rectal) aminosalicylate and a high-dose oral aminosalicylate if remission is not achieved within 4 weeks, stop topical treatments and offer a high-dose oral aminosalicylate and an oral corticosteroid

Managment of mil-moderate colitis (includes flares) - Proctitis

topical (rectal) aminosalicylate: for distal colitis rectal mesalazine has been shown to be superior to rectal steroids and oral aminosalicylates. if remission is not achieved within 4 weeks, add an oral aminosalicylate if remission still not achieved add topical or oral corticosteroid