LARGE BOWEL
IBDINFLAMMATORY BOWEL DISEASESchronic inflammatory bowel diseases (Ulcerative colitis and Crohn's disease)
Characters: relapsing and remitting course. (2) The diseases have many similarities and it is sometimes impossible to differentiate between them. (3) ulcerative colitis only involves the colon, while Crohn's disease can involve any part of the gastrointestinal tract from mouth to anus.Epidemiology
1. Crohn's disease appears to be very rare in the developing world but ulcerative colitis, is becoming more common. 2. In the West, the prevalence of ulcerative colitis 100-200 per 100 000, while the prevalence of Crohn's disease is 50-100 per 100 000. 3. Both diseases most commonly start in young adults (20-40) years, with a second incidence peak in the seventh decade.FACTORS ASSOCIATED WITH THE DEVELOPMENT OF IBD
Genetic factors 1. More common in Ashkenazi Jews 2. 10% have a first-degree relative or at least one close relative with IBD 3. High concordance between identical twins 4. Association with autoimmune thyroiditis and SLE 5. Gene mutations on chromosome 16 and some time on chromosomes 12, 6 and 14. 6. HLA-DR association in severe ulcerative colitis and with HLA-B27 and ankylosing spondylitis in both (UC and CD) commonly developEnvironmental Ulcerative colitis-more common in non-smokers and ex-smokers Crohn's-most patients are smokers Associated with low-residue, high refined sugar diet Appendicectomy protects against ulcerative colitis
PATHOLOGY
1. In both diseases the intestinal wall is infiltrated with acute and chronic inflammatory cells. 2. There are important differences in the distribution of disease and in histological featuresSITE OF INVOLVEMENT
UC
1. Inflammation is almost always involves and start from the rectum (proctitis). 2. It may spread proximally to involve the sigmoid colon (proctosigmoiditis) 3, and in a minority the whole colon is involved (pancolitis). 4. Inflammation is confluent and is more severe distally. 5. In long-standing pancolitis the bowel becomes shortened and 'pseudopolyps' develop which represent normal or hypertrophied residual mucosa within areas of atrophy
HISTOPATHOLOGY the inflammatory process is limited to the mucosa (not involve the deeper layers) of the colon (2) Both acute and chronic inflammatory cells infiltrate the lamina propria and the crypts ('cryptitis'). (3) Crypt abscesses are typical. (4) Goblet cells lose their mucus and in long-standing cases glands become distorted. (5) Dysplasia occurs and may lead to the development of colon cancer
NORMAL HISTOLOGY-COLON
UC PATHOLOGYCD - PATHOLOGY
The sites most commonly involved, in order of frequency, are: 1. terminal ileum and right side of colon 2. colon alone 3. terminal ileum alone 4. ileum and jejunumFistulae may develop between adjacent loops of bowel or between affected segments of bowel and the bladder, uterus or vagina, and may appear in the perineum.
a. The changes are patchy and interrupted by islands of normal mucosa ('skip' lesion). b. The mesenteric lymph nodes are enlarged and the mesentery thickened.
Histology: 1. chronic inflammation is seen through all the layers of the bowel wall, which is thickened as a result. 2. focal aggregates of epithelioid histiocytes, which may be surrounded by lymphocytes and contain giant cells. 3. Lymphoid aggregates or microgranulomas are also seen, and when these are near to the surface of the mucosa they often ulcerate to form tiny aphthous-like ulcers.
CD GRANULOMA
CLINICAL FEATURESUCThe major symptom is bloody diarrhoea
GENERAL FEATURES 1. The first attack is usually the most severe and thereafter the disease is followed by relapses and remissions. 2. Only a minority of patients have chronic, unremitting symptoms. 3. Emotional stress, intercurrent infection, gastroenteritis, antibiotics or NSAID therapy may provoke a relapse. 4. The clinical features depend upon the site and activity of the diseaseINVOLVES LARGE BOWEL ONLY
CLINICAL FEATURES ACCORDING TO SITE INVOLVED 1. Rectal involvement (Proctitis) causes: a. rectal bleeding b. mucus discharge c. tenesmus. d. Some patients pass frequent, small-volume fluid stools. e. others are constipated and pass pellety stools. f. Constitutional symptoms do not occur2. Rectum and sigmoid (Proctosigmoiditis) cause a. Bloody diarrhoea with mucus. b. Almost all patients are constitutionally well but a small minority who have very active, limited disease develop fever, lethargy and abdominal discomfort 3. The whole colon Extensive colitis causes a. bloody diarrhoea with passage of mucus. b. In severe cases anorexia, malaise, weight loss and abdominal pain occur, and the patient is toxic with fever, tachycardia and signs of peritoneal inflammation
CDThe major symptoms are abdominal pain, diarrhoea and weight loss
LARGE AND SMALL BOWEL1. Ileal Crohn's disease (small bowel) causes 1. abdominal pain, principally because of subacute intestinal obstruction, but inflammatory mass, intra-abdominal abscess or acute obstruction may be responsible. 2. Pain is often associated with diarrhoea which is watery and does not contain blood or mucus. 3. Weight lose almost always occur ( because eating provokes pain and also may be due to malabsorption). 4. Some patients present with features of fat, protein or vitamin deficiencies e. g. B12 due to malabsorption. B12 def. causes anaemia and neuropathy.
2. Crohn's colitis presents similar to ulcerative colitis. a. Bloody diarrhoea. b. Passage of mucus. c. Constitutional symptoms including lethargy, malaise, anorexia and weight loss. d. Rectal sparing and the presence of perianal disease are features which favour a diagnosis of Crohn's disease rather than ulcerative colitis.
3. Many patients present with symptoms of both small bowel and colonic disease. 4. A few have isolated perianal disease, vomiting from jejunal strictures or severe oral ulceration 5. Physical examination: a. Evidence of weight loss. b. Anaemia
c. Glossitis and angular stomatitis. d. There is abdominal tenderness, most marked over the inflamed area. e. An abdominal mass due to matted loops of thickened bowel or an intra-abdominal abscess may occur. f. Perianal skin tags, fissures or fistulae are found in at least 50% of patients
COMPLICATION OF IBD
INTESTINAL COMPLICATIONS
Toxic megacolon (mainly in ulcerative colitis).Intestinal perforation (small and large-in both).Haemorrhage (in both but rare).Fistulae (in Crohn’s disease).Colonic cancer (in ulcerative colitis and to lesser extend in Crohn’s colitis).Small bowel adenocarcinoma (in Crohn’s disease).1. TOXIC MEGACOLON: Is severe, life-threatening inflammation of the colon, occurs in both ulcerative colitis and Crohn's disease. the colon dilates (toxic megacolon) and bacterial toxins pass freely across the diseased mucosa into the portal then systemic circulation. This complication occurs most commonly during the first attack of colitis .
An abdominal X-ray should be taken daily because when the transverse colon is dilated to more than 6 cm there is a high risk of colonic perforation.
2. Perforation of the small intestine or colon: This can occur without the development of toxic megacolon 3. Life-threatening acute haemorrhage due to erosion of a major artery is a rare complication of both. 4. Fistulae : Fistulous connections between loops of affected bowel, or between bowel and bladder or vagina are specific complications of Crohn's disease and do not occur in ulcerative colitis.
5. increased risk of colon cancer in patients with extensive active colitis of more than 8 years' duration especially in UC. 6. Small bowel adenocarcinoma is a rare complication of long-standing small bowel Crohn's disease.
SYSTEMIC COMPLICATIONS OF IBD
Seronegative arthritis: a. Acute medium size joint involvement. b. Sacroiliatis. c. Ankylosing spondylitis. 2. Dermatological: a. erythema nodosum. b. Pyoderma gangrenosum. c. oral aphthous ulcers.3. Ocular complications: a. Conjunctivitis. b. iritis. c. episcleritis. 4. Hepatic and billiary: a. Primary sclerosing choliangitis (UC). b. Gall stone. c. Autoimmune hepatitis. d. fatty liver. e. Portal pyaemia and liver abscess.
5. Renal complications: a. Oxalate calculi (Crohn’s). b. Amyloidosis. c. Ureteric obstruction (Crohn’s).6. Vascular: a. DVT b. Portal or mesenteric vein thrombosis.
FOLLOW UP
surveillance colonoscopy programmes Patients with long-standing (8-10 years) extensive colitis (total) . Multiple random biopsies are taken every 10 cm throughout the colon and additional biopsies are taken from raised or ulcerated areas. Mild dysplesia: Do colonoscopy every 1-2 years. If high dysplesia: Do proctocolonectomy.MICROSCOPIC COLITIS
Some patients experience watery diarrhoea as a consequence of microscopic ('lymphocytic') colitis. The colonoscopic appearances are normal but histological examination of biopsies shows a range of abnormalities.
Collagenous colitis Is a type of microscopic colitis, characterised by the presence of a thick submucosal band of collagen; a chronic inflammatory infiltrate is usually seen. The disease is more common in women and is associated with rheumatoid arthritis, diabetes and coeliac disease. Patients have a history of intermittent watery diarrhoea and treatment is based on anti-diarrhoeal drugs, bismuth, aminosalicylates and topical corticosteroid enemas.
COMPARISON BETWEEN UC AND CD
UC more in non-smoker or ex-smoker, while CD more common in smoker. Sever UC is associated with HLA-DR103, while CD with chromosome 16 mutation (CARD15/NOD2). Involve colon , start from rectum and extend proximally, the lesions are confluent. CD involve any part of GIT from mouth to anus, perianal lesions and lesion are patchy with skip-lesion.4. Extra-intestinal involvement is common in both. 5. In UC: Main presentation is bloody diarrhea, while in CD: Abdominal pain, diarrhea and weight loss. 6. In UC the lesions are limited to mucosa with cryptitis and crypt abscess, but in CD submucosa, transmural, deep fissuring ulcers, fistula, patchy changes and granuloma. 7. R of UC: 5ASA, steroid, azathioprine, colectomy is curable. In CD: steroid, azathioprine, methotrexate, infliximab, nutritional R, surgery for complications is not curable.
Differential diagnosis of IBD
CONDITIONS WHICH CAN MIMIC ULCERATIVE OR CROHN'S COLITIS Infective (with first attack of IBD colitis) Bacterial Salmonella Shigella Campylobacter jejuni E. coli O:157 Gonococcal proctitis Pseudomembranous colitis (Antibiotics) Chlamydia proctitisViral Herpes simplex proctitis Cytomegalovirus Protozoal Amoebiasis
The major diagnostic difficulty is to distinguish the first attack of acute colitis from infection. In general, diarrhoea lasting longer than 10 days is unlikely to be the result of infection. Stool microscopy, culture and examination for Clostridium difficile toxin or for ova and cysts, sigmoidoscopy and rectal biopsy. blood cultures and serological tests for infection are usefulDIFFERENTIAL DIAGNOSIS OF SMALL BOWEL CROHN'S DISEASE
Other causes of right iliac fossa mass Caecal carcinoma Appendix abscess Infection (TB, Yersinia, actinomycosis) Mesenteric adenitis Pelvic inflammatory disease Lymphoma
Investigations of IBD Blood examination Full blood count may show anaemia resulting from bleeding or malabsorption of iron, folic acid or vitamin B12. Serum albumin concentration falls as a consequence of protein-losing enteropathy, or because of poor nutrition. The ESR is raised in exacerbations or because of abscess. Elevation of CRP concentration is helpful in monitoring Crohn's disease activity
Bacteriology Stool cultures are performed to exclude superimposed enteric infection in patients who present with exacerbations of IBD. Blood cultures are also advisable in patients with known colitis or Crohn's disease who develop fever.
Sigmoidoscopy and/or colonoscopy: A. Ulcerative colitis loss of vascular pattern. granularity. friability and ulceration. Also pseudopolyps, And carcinoma.
NORMAL RECTUM
NORMAL SIGMOID COLONNORMAL SPLENIC FLEXURE
NORMAL TRANVERSE COLONNORMAL ASCENDING COLON
UC GROSSUC
B. In Crohn's disease patchy inflammation with discrete, deep ulcers or aphthus like ulcers. perianal disease (fissures, fistulae and skin tags) or rectal sparing may occur.
CAPSULE ENDOSCOPY
Barium studies Barium enema is a less sensitive investigation than colonoscopy. In long-standing ulcerative colitis the colon is shortened and loses haustra to become tubular, and pseudopolyps are seen. In Crohn's colitis a range of abnormalities occur. The appearances may be identical to those of ulcerative colitis but skip lesions, strictures and deeper ulcers are characteristic .Reflux into the terminal ileum may show stricture and ulcers. Contrast studies of the small bowel are normal in ulcerative colitis, but in Crohn's disease affected areas are narrowed and ulcerated; multiple strictures are common .
Plain abdominal X-ray is essential in the management of patients who present with severe active disease. Dilatation of the colon , mucosal oedema ('thumb-printing') or evidence of perforation may be found. In small bowel Crohn's disease there may be evidence of intestinal obstruction or displacement of bowel loops by a mass. Ultrasound may identify thickened small bowel loops and abscess development in Crohn's disease.
Diagnosis of Small bowel Crohn's disease 1. white cell scanning may help identify inflamed intestinal segments. 2. In atypical cases biopsy or surgical resection is necessary to exclude other diseases . This can often be done endoscopically by ileal intubation at colonoscopy, but sometimes laparotomy or laparoscopy with resection or full-thickness biopsy is necessary.
Aim of treatment
1. To treat acute attacks 2. To prevent relapses 3. To detect carcinoma at an early stage 4. To select patients for surgery.Methylprednisolone IV Drip (SEVERE IBD)
Cyclosporine IV drip(SEVERE UC)Biological AgentsInfliximab 5mg/kg, IV drip (0, 2W, 6Ws. Adalimumab (subcutaneous)
Thiopurines Maintenance therapy / steroid sparingMedical management of ulcerative colitis
Treatment depends upon the extent and activity of colitis.Active proctitis
Active left-sided or extensive ulcerative colitis
Severe ulcerative colitis
Active proctitis 1. In mild to moderate disease Mesalazine (5ASA) enemas or suppositories combined with oral mesalazine are effective first-line therapy. 2. Topical corticosteroids are less effective and are reserved for patients who are intolerant of topical mesalazine. 3. Patients who fail to respond are treated with oral prednisolone 40 mg daily.Active left-sided or extensive ulcerative colitis In mildly active cases, high-dose aminosalicylates( Mesalazine) combined with topical aminosalicylate and corticosteroids are effective. Oral Prednisolone 40 mg daily is indicated for more active disease or when initial aminosalicylate therapy is ineffective.
Severe ulcerative colitisAdmit to hospital.Systemic high doses of steroid (iv methyl prednisolone or hydrocortisone).Supportive treatment like iv fluid, blood transfusion and nutritional support.Antibiotic therapy if infection is evidence of infection.Lab tests (Hb, ESR, Electrolytes, S. Urea….)
Plain X-ray of abdomen to exclude toxic megacolon. DVT prophylaxis by Heparin. Avoid opiates and anti-diarrheal agents. Iv ciclosporin (cyclosporine) (2mg/kg) or infliximab (5mg/kg) in patients not responding to 3-5 days of steroid therapy. If Patient not responding to above treatment or develop toxic megacolon consider surgery (total colectomy).
INDICATIONS FOR SURGERY IN ULCERATIVE COLITIS
Impaired quality of life Failure of medical therapy Fulminant colitis Disease complications unresponsive to medical therapy Colon cancer or severe dysplasiaR OF ACTIVE CROHN’S DISEASE Patients with active colitis or ileocolitis are initially treated in a similar manner to those with active ulcerative colitis. Aminosalicylates and corticosteroids are both effective and usually effect remission in active ileocolitis and colitis. In severe disease intravenous prednisolone is indicated, but abscess or fistulating disease should be excluded before instituting therapy with corticosteroids.
R OF ILEAL DISEASE IN CD
1. Steroid: Budesonide is appropriate for treating moderately active disease, although it is marginally less effective thanprednisolone. Aminosalicylates have little added value there is some evidence to support the use of oral metronodazole. Poorly responding patients should, at an early stage, be considered for surgical resection since this is associated with prolonged remission in most cases.4. Infliximab (anti-TNF monoclonal antibody ) given as an intravenous infusion 4-8-weekly on three occasions induces remission in patients with active Crohn's disease at any site within the gastrointestinal tract and is also effective for the management of some extraintestinal complications including pyoderma gangrenosum and some forms of arthritis. combined with disease-modifying agents, either thiopurines or methotrexate, to maintain remission. 5. nutritional support which in the most severe cases involves prolonged parenteral nutrition
Maintenance of remission
The most effective step, and one greater than any pharmacological intervention, is smoking cessation. Unlike UC Aaminosalicylates have minimal efficacy. Patients who relapse more than once a year are treated with thiopurines . Those patients who are intolerant of, or resistant to azathioprine or 6-mercaptopurine are treated with once-weekly methotrexate combined with folic acid. Patients with aggressive disease are managed using a combination of immunomodulating agents and infliximab . Chronic use of corticosteroids is avoided since this leads to osteopenia and other side-effects, without preventing relapse.