Crohn's Disease and Ulcerative Colitis

Both the diseases, Ulcerative Colitis and Crohn's Disease, while seemingly related, are distinct diseases in terms of etiology, pathology, clinical presentation and prognosis. A summary table highlighting these attributes in presented below:

Sex Ratio02:01:0001:01:00
Role of Genetics in causationGreaterMinimal or nil
Cigarette-smoking RelationshipSmokers are at greater risk of developing CD (nicotine can aggravate disease)Ex-smokers and Non-smokers are at greater risk of developing UC (nicotine may be preventive)
Immunological CulpritInflammation though to be triggered by Th1 cells; IL-12 is increasedInflammation though to be triggered by Th2 cells; IL-5 is increased
Commonly Involved areasIleum & Proximal ColonDistal Colon & Rectum
Typical symptomsAbdominal pain, weight loss, diarrhea, feverAbdominal pain, weight loss, diarrhea, rectal bleeding,
Blood & mucus from rectumRareCommon
Abdominal massMay be present in right-lower quadrant of abdomenRare
Extra-intestinal manifestationsCommonCommon
Ileus (reduced or absent motility of intestines)CommonRare
Colonic obstructionCommonRare
Perianal fistulaCommonNo
Protein-Calorie MalnutritionMore likely (25-80% have hypoalbuminemia)Less likely (25-50% have hypoalbuminemia)
Nutritional statusRelatively poorBetter preserved
Nature of InvolvementInterrupted lesions (skip-lesions common)Uninterrupted lesions
Extent of InflammationTransmural (can extend through the thickness of the wall)Limited to mucosa
Associated lesions/pathologiesStrictures, Fistulas, GranulomasNone of these