Crohn's disease is a chronic inflammatory bowel disease (IBD) characterized by inflammation of the digestive tract. It can affect any part of the gastrointestinal (GI) tract, from the mouth to the anus, but most commonly involves the end of the small intestine (ileum) and the beginning of the colon. Crohn's disease is a lifelong condition with periods of active disease (flares) and periods of remission. **Key features of Crohn's disease include:** 1. **Inflammation:** The hallmark of Crohn's disease is chronic inflammation that can extend deep into the layers of the affected bowel tissue. This inflammation can lead to various symptoms and complications. 2. **Symptoms:** Common symptoms include abdominal pain, diarrhea, weight loss, fatigue, and sometimes fever. The severity and specific symptoms can vary widely among individuals. 3. **Patchy Involvement:** Crohn's disease often involves "skip lesions," meaning that inflamed areas are interspersed with healthy portions of the bowel. This patchy involvement distinguishes Crohn's from other inflammatory bowel diseases like ulcerative colitis. 4. **Complications:** Inflammation in Crohn's disease can lead to complications such as strictures (narrowing of the intestine), fistulas (abnormal connections between different parts of the intestine or between the intestine and other organs), and abscesses. 5. **Extraintestinal Manifestations:** Crohn's disease can also affect other parts of the body outside the digestive tract, leading to conditions such as arthritis, skin problems, and inflammation of the eyes. 6. **Onset and Course:** Crohn's disease can develop at any age but is often diagnosed in young adulthood. The course of the disease is unpredictable, with periods of exacerbation and remission. 7. **Contributing Factors:** The exact cause of Crohn's disease is unknown, but a combination of genetic, environmental, and immune system factors is believed to play a role. Smoking is a significant risk factor for developing Crohn's disease. 8. **Diagnosis and Treatment:** Diagnosis involves a combination of medical history, physical examination, imaging studies, endoscopy, and laboratory tests. Treatment aims to control inflammation, relieve symptoms, and improve quality of life. Medications, lifestyle changes, and, in some cases, surgery may be part of the treatment plan. It's important for individuals with Crohn's disease to work closely with healthcare professionals to manage their condition effectively, as well as to address the potential impact on nutrition, mental health, and overall well-being.

1. CROHN'S DISEASE PATHOLOGY
M.Saihetharan BSC(hones) in Biomedical science(R) KIU
Advances cert in Immunology and molecular biology
(university of colombo)

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INTRODUCTION
• Crohn’s disease is a chronic disease that causes inflammation and
irritation in your digestive tract.
• Most commonly, Crohn’s affects your small intestine and the
beginning of your large intestine.
• However, the disease can affect any part of your digestive tract,
from your mouth to your anus.

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ETIOLOGY OF THE DISEASE
There’s no known cause of Crohn’s disease. Certain factors may
increase your risk of developing the condition, including:
• Autoimmune disease: Bacteria in the digestive tract may cause
the body’s immune system to attack your healthy cells.

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 Genes: Inflammatory bowel disease (IBD) often runs in families. If
you have a parent, sibling or other family member with Crohn’s, you
may be at an increased risk of also having it. There are several
specific mutations (changes) to your genes that can predispose
people to developing Crohn’s disease.
Smoking: Cigarette smoking could as much as double your risk of
Crohn’s disease

5. PATHOGENESIS OF THE DISEASE
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 An increased permeability of the mucous membrane
 This may lead to increased passage of luminal antigens, which then
induce a cell-mediated inflammatory response
 This results in the release of proinflammatory cytokines, such as
interleukin -2 and tumor necrosis factor, which co-ordinate local
and systemic inflammatory responses

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 Potentially genetically determined increased in gut permeability, combined with
an abnormal immune-mediated response to colonization of the gut with
subspecies of the normal enteric micro flora may initiate the disease

7. MACROSCOPIC AND MICROSCOPIC FEATURES
Skip lesions
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Macroscopic Features
 The Wall of the affected bowel segment is
thick and hard resembling a hose pipe
 Serosa may be studded with minute
granulomas

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 The mucosa shows serpiginous ulcers
while surviving mucosa is swollen
giving cobblestone appearance
 There may be deep issuing in bowel wall

10. MICROSCOPIC
FEATURES
Transmural inflammatory
Non caseating sarcoid like
granulomas
Patchy ulceration
Disrupted architecture
Paneth cell metaplasia
Cryptitis crypt abscesses
SAMPLE FOOTER TEXT 20XX 10

11. Crypts and crypt abscess
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Non caseating granuloma

12. COMPLICATION OF DISEASE
 Malabsorption
 Fistula formation
 Stricture formation
 Development of malignancy
 Anemia
 Colon cancer
 Skin and eye problems
 Abscesses
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13. TREATMENT OF DISEASE
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 Medication reduces inflammation and promotes long-term remission.
 Long-term use of corticosteroids has significant side
 Alternatives to amino salicylates are available, but only a minority can maintain
them
 Immunosuppressant drugs:
 Immunosuppressants are most used to treatment of Crohn’s disease
 Eg: azathioprine, mercaptopurine
Mediation

14. Surgery
 Crohn’s cannot be cured by surgery
 Surgery required in case of
obstructions, abscesses, or if the
disease doesn’t respond to drugs.
 Remove diseased portion of
intestine
 Anastomosis connects remaining
bowel
Nutrition
 Eating a low animal fat diet-30%
of energy requirements.
 Avoid foods high in insoluble
fiber
 Include supplemental vitamin d
and dairy products if tolerated.
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15. REFERENCES
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1. Petagna, L., Antonelli, A., Ganini, C., Bellato, V., Campanelli, M., Divizia, A., Efrati, C., Franceschilli, M., Guida, A.
M., Ingallinella, S., Montagnese, F., Sensi, B., Siragusa, L., & Sica, G. S. (2020, November 7). Pathophysiology of
Crohn’s disease inflammation and recurrence. PubMed Central (PMC). https://doi.org/10.1186/s13062-020-
00280-5
2. Petagna, L., Antonelli, A., Ganini, C., Bellato, V., Campanelli, M., Divizia, A., Efrati, C., Franceschilli, M., Guida, A.
M., Ingallinella, S., Montagnese, F., Sensi, B., Siragusa, L., & Sica, G. S. (2020, November 7). Pathophysiology of
Crohn’s disease inflammation and recurrence. PubMed Central (PMC). https://doi.org/10.1186/s13062-020-
00280-5
3. A Text-Book of Pathology. (2016, August 29). Wentworth Press.
4. Crohn’s disease - Symptoms and causes. (2022, August 6). Mayo Clinic. https://www.mayoclinic.org/diseases-
conditions/crohns-disease/symptoms-causes/syc-20353304
5. Hytowitz, A. N. (2023, January). Review of using the Dyop optotype for acuity and refractions per the article:
https://www.sciencedirect.com/science/article/pii/S1888429622000656. Journal of Optometry.
https://doi.org/10.1016/j.optom.2022.12.002
6. Chase, C. (2015, July 29). Crohns Disease: The Ultimate Guide for the Treatment and Relief from Crohn’s Disease
( Crohns Disease Crohns Cookbook).

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