Inflammatory Bowel Diseases
Inflammatory Bowel Diseases Introduction:
Table of Contents
These are the diseases involving small and large bowel, of unknown aetiology, characterised by multiple ulcerations in the bowel, clinically manifesting as blood and mucus in stools. Ulcerative colitis and Crohn’s disease (regional enteritis) are included under this heading. Both diseases can present as acute abdomen with intestinal obstruction and complications such as perforation toxaemia, etAlso both are premalignant conditions for carcinoma colon. Ulcerative colitis is a mucosal disease and Crohn’s is a transmural disease.
Ulcerative Colitis
Aetiology:
- Autoimmune factor: Even though exact mechanism of ulcerative colitis is not clear, there are some factors which may point out to autoimmune reaction. They are:
- Presence of cytotoxic T lymphocytes against colonic epithelial cells in the lamina propria of the bowel.
- Presence of anticolon antibodies.
- Whatever be the immune mechanisms, activation of inflammatory mediators such as cytokines, growth factors and arachidonic acids takes place and they are responsible for the disease.
- Dysfunctional immunoregulation in the intestinal wall results in inappropriate production of cytokines. This creates an imbalance between various interleukins resulting in inflammatory changes.
- Psychosomatic and personality factors: Ulcerative colitis is more common in western women. Emotional stress, family stress, and stress from divorce are the contributing factors. Periods of activity and remission is common.
- Dietary factors
- Westernisation of the diet which is rich in red meat has been blameVegetarian diet is supposed to protect the colonic mucosa.
- Allergy to milk protein is responsible for ulcerative colitis in a few patients.
- Defective mucin production and a defective mucosal immunological reaction is considered as a chief factor responsible for ulcerative colitis.
- Genetic: 15% of patients have first degree relatives with ulcerative colitis.
Ulcerative Colitis Pathology:
- The disease always starts in the rectum and spreads in a backward manner, thus involving the entire colon in majority of cases. In 5% of cases, terminal ileum can also be involved—back wash ileitis.
- Anus is not involved in ulcerative colitis.
- The disease manifests as multiple, small superficial ulcers—pinpoint ulcers.
- As the disease progresses, inflammation spreads into the submucosa of the colon.
- Destruction of muscle is described as myocytolysis. Attempt at healing may produce pseudopolyp. There are areas of epithelial hypertrophy in between the ulcers, resembling polyp. Healing with fibrosis results in a narrow, contracted colon, called pipe stem colon.
- Microscopy: Pus (abscess) in the crypts and pus cells (inflammatory cells) in the lamina propria are typical of ulcerative colitis.
- Long-standing cases will change into dysplasia of the epithelium—dysplasia associated lesion (DAL).
Ulcerative Colitis Clinical Features:
- More common in females. Female:male ratio is 2:1.
- Age: Common age of presentation is 3rd decade followed by 4th and 2nd decades.
- The disease is characterised by passage of 15–20 stools per day and contains blood and mucus. Sometimes, it may be watery diarrhoeAs the rectum loses elasticity and lumen collapses, tenesmus occurs.
- Relapses and remissions are common and are related to emotional disturbances. Tenesmus, urgency with severe inflammation result in incontinence.
- Severe dehydration, malnutrition, anaemia, hypoproteinaemia are late features.
- Acute fulminating attack is associated with high grade fever, bloody dysentery, distension and tenderness all over the abdomen with profound weakness. Hypokalaemia, acidosis, anaemia and shock are the other features.
Clinical Findings in Severe Disease:
- Temperature
- Tachycardia
- Tender colon—abdomen
- Tenesmus—anaemia, hypoproteinaemia
- Terrific disease—dehydration, hypokalaemia, acidosis, shock
Types of Ulcerative Colitis (depending upon the extent of the colon involved)
- Proctitis: In about 20–25% of the patients, the disease involves only rectum. In such patients, stools are semisolid because of absorption of water by normal colon. Also, the intensity of the disease is not severe and risk of cancer is 2–5%.
- Left-sided colitis: It is found in 15% of patients. It presents as severe recurrent attacks of diarrhea with blood in stools, without systemic toxicity.
- Total proctocolitis: It is seen in about 25% of the patients. Severe bloody diarrhoea and hypoproteinaemia are its features. Chances of cancer and complications are high in this group.
Ulcerative Colitis Complications:
1. Toxic megacolon: It is an abdominal emergency encountered with fulminating colitis. Severe abdominal pain and tenderness, toxaemia, high fever, tachycardia and leucocytosis are the features. Plain X-ray abdomen which shows colon with a diameter more than 6 cm gives the diagnosis. It requires emergency treatment by laparotomy and colectomy. Local inflammatory mediators such as interleukins and nitric oxide are released from smooth muscles. Activities of macrophages are also increaseThis results in colonic dysmotility and toxic dilatation. As a result, mucosal sloughing, bacterial translocation, perforation/septicaemia and death can occur in untreated cases. Antidiarrhoeals, anticholinergics, narcotics, and hypokalaemia exaggerate this condition. Supportive treatment and intravenous corticosteroids are necessary
2. Massive haemorrhage per rectum is uncommon. It is treated by blood transfusion.
3. Perforation is treated as peritonitis with resection of colon. Mortality rate is around 25–50%. Steroids may mask the symptoms. In an emergency situation, saving life is more important. Hence, resection followed by ileostomy should be done.
4. Carcinoma of the colon:
- The overall incidence is 3% when the disease has been present for 15 years.
- At the end of 25 years, the incidence may be around 20%.
- Hence, routine sigmoidoscopy and biopsy have to be done when the disease is present for more than 10 years and if it shows epithelial dysplasia, it should be considered as premalignant.
- Incidence is more in total proctocolitis and when the disease has started in the early age group.
5. Recurrent perianal abscess resulting in perianal fistula, occurs in about 15–20% of patients.
6. General complications (extraintestinal):
- Protein malnutrition resulting in cirrhosis.
- Primary sclerosing cholangitis is also found in many cases. Fatty acid infiltration is seen in 40% of cases. It is reversible after control of disease.
- Skin ulcerations, pyoderma, erythema nodosum, etreflect protein malnutrition.
- Conjunctivitis, iritis, arthritis involving large joints are also other features.
- Incidence of bile duct cancer is high in these patients.
Ulcerative Colitis Differential Diagnosis
- Crohn’s disease should be ruled out first. The differences between the two inflammatory bowel diseases have been discussed at the end of the chapter. In general, diarrhoea and bleeding are more common with ulcerative colitis than Crohn’s disease.
- Dysenteries: Bacillary dysenteries, shigellosis, salmonellosis, amoebiasis and other dysenteries have to be kept in mind specially in developing countries including tuberculosis which has been already discussed.
- Diverticular disease of the colon: However, when complications including bleeding occur, diverticular disease of the colon and in cases of perforations, malignant perforation must be considered as a differential diagnosis.
Ulcerative Colitis Investigations
1. Stool: It is done mainly to rule out various causes of infective diarrhoea—amoebiasis, Shigella, Clostridium difficile. Most common cause of infective colitis in UK is Campylobacterium.
2. Sigmoidoscopy: Can demonstrate inflammatory changes in the mucosMucus, pus and blood are visible. Multiple ulcers are visible with bleeding.
3. Barium enema findings in ulcerative colitis (should not be done in acute cases)
- Contracted colon/pipe stem colon
- Absence of haustrations and mucosal irregularity
- Pseudopolyposis appears as stippled appearance
- Retrorectal space is increased.
4. Colonoscopy:
- To confirm the diagnosis by biopsy
- To find out the extent of involvement of colon
- To follow up patients who are on treatment
- To rule out carcinomatous changes
5. Plain X-ray abdomen: To rule out megacolon and perforation.
6. C-reactive protein: Its levels are very high in case of acute fulminating attack or toxic megacolon.
7. Electrolytes, albumin levels are low. They have to be corrected especially in severe cases.
Treatment of Ulcerative Colitis
1. Conservative Line of Management:
- Hospitalisation and bed rest
- Correction of fluid and electrolyte imbalance
- Blood transfusions to correct anaemia and TPN for hypoproteinaemia.
- Salazopyrines are given in the dose of 2 g/day. Mode of action: When given orally, it gets split into 5- aminosalicylic acid and sulphapyridine in the colon. This suppresses activity of prostaglandins E1 and E2 and thus reduces inflammation. They are used mainly to induce remission. They act as inhibitors of the cyclooxygenase enzyme system.
- Corticosteroids: Less severe cases not responding to salazopyrines are given a trial of oral prednisolone 60 mg/day. They decrease the frequency of stools. The dose is tapered off over 3–4 weeks.
- In acute attacks, IV hydrocortisone 100 mg is given.
- Prednisolone retention enema: 20 mg in 200 ml saline in intractable diarrhoeIt avoids systemic toxicity. Prednisolone 20–40 mg/day can also be given orally for 3–4 weeks.
- Role of cyclosporine: Those patients who do not respond to corticosteroids, can be given IV cyclosporine 4 mg/kg/day. It can induce remission.
- Role of monoclonal antibodies: These drugs act against antitumour necrosis factor alphThey regulate inflammatory cascades. Infliximab or adalimumab are drugs. Vedolizumab is a rescue agent which blocks integrins.
2. Surgery:
Indications for Surgery:
- Complications—toxic megacolon, perforation.
- Active disease in spite of medical line of management
- Severe disease not responding to medical treatment
- Dysplasia on biopsy
- Steroid dependence
- Haemorrhage
1. Restorative proctocolectomy with ileal pouch:
- This can be done as one- or two-stage procedure.
- Total proctocolectomy is done first.
- A mucosectomy of the upper anal canal is done.
- A pouch is created by anastomosing the loops of ileum. A J-shaped pouch is the most popular followed by W pouch.
Pharmacotherapy in ulcerative colitis:
- The pouch is anastomosed to the dentate line (junction of upper and lower anal canal) by using stapler or by hand sutures.
- Protective ileostomy is done and it can be closed after two months.
2. Total proctocolectomy followed by permanent ileostomy (ileoanal anastomosis should not be done because of incontinence). Ileostomy is connected to ileostomy bag. Adhesive obstruction and chronic perineal sinus are late complications. This is the procedure with least complications.
Advantages of a pouch:
- Avoids ileostomy.
- Continence is preserved and patient is able to pass the stools via naturalis.
- At the same time, all the diseased mucosa has been removeThus, the risk of cancer is negligible.
- Pouchitis is a complication.
Complications of pouch:
- Inflammation of the pelvis due to leak.
- Adhesion causing postoperative intestinal obstruction.
- Pouch—vaginal fistula.
- Frequency of the stools around 4 to 10 times/day.
- Pouchitis: It is inflammation of the pouch. Seen in about 30% of patients. Features represent original disease such as tenesmus, frequency of stools, toxicity, etMetronidazole can be used to treat.
Ulcerative Colitis Prognosis:
In general, emergency colitis is required in about 25% patients with severe attacks. Perforation has a mortality rate of up to 40% because of faecal contents and toxicity. Incidence of carcinoma colon is about 10–15%. Longer the duration of the disease, higher is the incidence.
Treatment of ulcerative colitis:
Ulcerative Colitis Dietary Advice
- High protein, carbohydrates, whole grains, and good fats. Meat, fish, poultry, and dairy products, breads and cereals; fruits and vegetables may be consumed.
- For vegetarians: Dairy products and plant proteins— such as soya bean products may be consumed.
- To avoid: High fibre high residue diet—thus to control diarrhoea.
- To avoid: Caffeine—coffee, dried fruits and nuts, alcohol, meat, spicy food, oily food, soda, etc.
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