- Crohn’s disease can affect any part of the digestive tract
- Crohn’s disease lesions are often discontinuous
- Affects all layers of the bowel from the inner mucosa to the outer serosa
- The sites most commonly involved, in order of frequency are terminal ileum, and right side of colon, colon alone, terminal ileum alone, ileum and jejunum.
- Characteristically, the entire wall of the bowel is oedematous and thickened.
- There are deep ulcers which appear as linear fissures; thus the mucosa between them is described as cobblestone
- Deep ulcers may penetrate through the bowel wall to initiate abscesses or fistulae. Fistulae may develop between adjacent loops of bowel or between affected segments of bowel and the bladder, uterus or vagina and may appear perineum.
- Characteristically the changes are patchy . Even when short segment of bowel is affected the inflammatory process is interrupted by islands of normal mucosa and the changes from the affected part is abrupt.
- Skip area.
- The mesenteric lymph nodes are enlarged and the mesentery thickened.
- Histologically, chronic inflammation is seen through all the layers of the bowel wall which is thickened as a result. There are focal aggregates or microgranuloma are seen and when they are near to the surface of the mucosa they often ulcerate to form tiny aphthous –like ulcers.
- Diarrhea
- Abdominal pain and tenderness
- Loss of appetite and weight
- Fever
- Fatigue
- Rectal bleeding (less as compared to UC) and anal ulcers
- Stunted growth in children
CROHN’S DISEASE
Macroscopically, thickening due to edema and fibrosis, which can be severe enough to cause a stricture
Granuloma formation on the serosal surface
“Cobblestone” appearance due to a combination submucosal edema and fissuring ulcers
Apthoid (mild superficial) and fissure (severe deep) ulcers
Clinical Features
Crohn’s disease
Presentation depends o the major site of disease involvement
Ileal- abdominal pain associated with diarrhoea which is watery
No blood or mucus
Weight loss
Features of nutritional deficiency
- Rectal sparing and the presence of perianal disease are features which favour a diagnosis of Crohn’s disease rather than ulcerative colitis.
- Features of both small bowel and colonic disease.
- Physical exam-weight loss, anaemia with glossitis, angular stomatitis, abdominal tenderness and abdominal mass
Smoking in IBD
- Ulcerative Colitis
- Smoking can protect against UC
- Ex-smokers are more likely to develop UC
Crohn’s disease
- Twofold risk in current smokers
- Smokers are less responsive to treatment
- Recurrence of disease after surgery
Complications
Intestinal
- Severe life-thratenening inflammation of the colon
- Perforation of the small intestine or colon
- Life threatening acute hemorrhage
- Fistula and perianal disease
Extra intestinal
- Ocular
- Liver
- Mesenteric or portal vein thrombosis
- Venous thrombosis
- Arthralgia of large joints
- Erythema nodosum
- Pyoderma gangrenosum
- Metabolic bone disease
Nutritional complications are common in IBD:
deficiencies of proteins, calories, and vitamins.
These deficiencies may be caused by inadequate dietary intake, or poor absorption (malabsorption).
Other complications associated with IBD include:
arthritis, skin rashes, arthritis, inflammation of the eye or mouth, kidney stones, or other diseases of the liver and biliary system.
Treatment
- no cure for IBD but there is medical therapy and surgical therapy
- Medical therapy for IBD has three main goals:
- Inducing remission (periods of time that are
- symptom-free)
- Maintaining remission (preventing flare-ups
- of disease)
- Improving the patient’s quality of life
At the present time, there are five basic categories of medications used in the treatment of IBD. They are:
• Aminosalicylates
• Corticosteroids
• Immunomodulators
• Antibiotics
• Biologic therapies
5-Aminosalicylic Acids
- The mainstay treatment of mild to moderately active UC and CD (induction).
- 5-ASA may act by
- blocking the production of prostaglandins and leukotrienes,
- inhibiting bacterial peptide–induced neutrophil chemotaxis and adenosine-induced secretion,
- scavenging reactive oxygen metabolites
- For patients with distal colonic disease, a suppository or enema form will be most appropriate.
- Maintenance treatment with a 5-aminosalicylic acid can be effective for sustaining remission in ulcerative colitis but is of questionable value in Crohn's disease.
Corticosteroids
- Topical corticosteroids can be used as an alternative to 5-ASA in ulcerative proctitis or distal UC.
- Oral prednisone or prednisolone is used for moderately severe UC or CD, in doses ranging up to 60 mg per day.
- IV is warranted for patients who are sufficiently ill to require hospitalization; the majority will have a response within 7 to 10 days.
- No proven maintenance benefit in the treatment of either UC or CD.
- Many and serious side effects.
- Budesonide:
- less side effects,
- its use is limited to patients with distal ileal and right-sided colonic disease
Immunosuppressive Agents
- These agents are generally appropriate for patients in whom the dose of corticosteroids cannot be tapered or discontinued.
- Azathioprine & 6-MP
- The most extensively used immunosuppressive agents.
- The mechanisms of action unknown but may include
- suppressing the generation of a specific subgroup of T cells through inhibiton of calcineurin.
- The onset of benefit takes several weeks up to six months.
- Dose-related BM suppression is uniformly observed
- Methotrexate
- Effective in steroid-dependent active CD and in maintaining remission.
- Cyclosporine
- Severe UC not responding to IV steroid &needing urgent proctocolectomy.
- 50% of the responders will need surgery within a year.
- TNF inhibitors
- Infliximab
- Etanercept
INDICATIONS FOR SURGERY
In patients with UC:
- Severe attacks that fail to respond to medical therapy.
- Complications of a severe attack (e.g., perforation, acute dilatation).
- Chronic continuous disease with an impaired quality of life.
- Dysplasia or carcinoma.
- Obstruction, severe perianal disease unresponsive to medical therapy, difficult fistulas, major bleeding, severe disability
- 30 % relapse rate
UC:
- Risk of cancer begins after 8 years, risk of pancolitis 7% at 20 years and 17% at 30 years.
- Increased risk for cancer: early age of onset, pancolitis.
- Need for colonoscopic screening after 8 years
- True incidence of cancer is uncertain, but could be as high as UC
- Need the same screening policy.
