Inflammatory Bowel Disease (IBD)

* Definition: a chronic condition characterized by intestinal inflammation and ulceration that has no exact identifiable cause; may be genetic, immulogical or environmental.

* Course of the IBD: The inflammatory bowel disease is a chronic disease (lasting a long time), show periods of exacerbations in which the disease flares up and causes symptoms alternating with areas of remissions in which symptoms disappear or decrease.

* Symptoms include the followings: Abdominal cramps and pain. Bloody diarrhea. Fever. Loss of appetite . Weight loss. Anemia (due to blood loss). Extra-intestinal manifestations: arthritis, eye problems.

* Two common types of IBD: Ulcerative colitis. Crohn’s disease.

Ulcerative colitis

* Morphological features of UC: Site: Ulcerative colitis involves the rectum and extends proximally in a retrograde fashion to involve the entire colon ("pancolitis") in the more severe cases. The affected segment is diffusely inflamed and shows; Marked inflammatory cellular infiltrate of the mucosa by lymphocytes, plasma cells and neutrophils. Ulcerations.

Psudopolyps formation: hyperplastic surface mucosal cells without fibrovascular cores. Cryptitis and crypt abscess: presence of neutrophils inside colonic glands. Dysplasia of the colonic glands: which is precancerous.

Endoscopic image of a sigmoid colon with ulcerative colitis.

Colonic pseudopolyps

Marked lymphocytic infiltration (blue/purple) of the colonic mucosa.

Crypt abscess, a classic finding in ulcerative colitis

* Complications of UC: 1. Bleeding: Rectal bleeding and bloody diarrhea are two of the hallmark symptoms of ulcerative colitis. 2. Anemia: In ulcerative colitis, this is usually the result of chronic blood loss. 3. Malnutrition: Symptoms such as diarrhea and rectal bleeding can lead to a loss of fluids and nutrients.

4. Intestinal Stricture and obstruction: due to fibrosis. 5 4.Intestinal Stricture and obstruction: due to fibrosis. 5. Cancer colon: Ulcerative colitis patients have a higher risk of developing colon cancer. The risk increases when ulcerative colitis for a prolonged period of time.

6. Perforation: Extensive inflammation can lead to a tear in the intestinal wall, resulting in leakage of bowel contents outside the intestine. 7. Toxic megacolon: when inflammation spreads from the mucosa to involve the entire intestinal wall which temporarily stops the normal contractile movements of the intestine, and the large intestine may greatly expand.

Crohn's disease (Regional enteritis)

* Morphological features of Crohn's disease: * Site: any part of G.I.T, but the most common site is the terminal ileum. The affected part of the intestine show skip areas i.e. areas free from the lesions. The intestinal wall is thick and rubbery, caused by edema, inflammation, and fibrosis. Cobble stone appearance due to edema of the mucosa with interrupting fissuring ulcers.

Fissuring of the wall with formation of fistulae. Microscopically there is: transmural involvement of the bowel by mixed inflammatory cells and the presence of non-caseating granulomas.

Gross appearance of Crohn's disease Gross appearance of Crohn's disease. There is a sharp demarcation between the involved and the uninvolved areas.

Cobblestone appearance

Crohn's disease; transmural inflammation

Crohn's disease; showing marked inflammatory changes and the formation of a fissure.

Crohn’s disease; non-caseating epithioid granuloma

* Complications of crohn’s disease: 1. Intestinal obstruction: Blockage occurs because the disease tends to thicken the intestinal wall by inflammation and finally fibrosis occurs. 2. Fistulas: intestino-intestrinal, intestino-abdominal and perianal fistulae.

3. Malabsorption syndrome: deficiencies of proteins, calories, and vitamins deficiencies may be caused by inadequate dietary intake, intestinal loss of protein, or poor absorption.

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