Ulcerative colitis is characterised by diffuse mucosal inflammation limited to the colon. Disease extent can be broadly divided into distal and more extensive disease. “Distal” disease refers to colitis confined to the rectum (proctitis) or rectum and sigmoid colon (proctosigmoiditis). More extensive disease includes “left sided colitis” (up to the splenic flexure), “extensive colitis” (up to the hepatic flexure), and pancolitis (affecting the whole colon).Crohn’s disease is characterised by patchy, transmural inflammation, which may affect any part of the gastrointestinal tract. It may be defined by location (terminal ileal, colonic, ileocolic, upper gastrointestinal), or by pattern of disease (inflammatory, fistulating, or stricturing).
These variables have been combined in the Vienna classification. About 5% of patients with IBD affecting the colon are unclassifiable after considering clinical, radiological, endoscopic, and pathological criteria, because they have some features of both conditions. This can be termed indeterminate colitis (IC).Inflammatory bowel disease (IBD) involves chronic inflammation of all or part of your digestive tract. IBD primarily includes ulcerative colitis and Crohn's disease.Severe diarrhea, pain, fatigue and weight loss. IBD can be debilitating and sometimes leads to life-threatening complications.Doctors use one of two approaches to treatment: "step-up," which starts with milder drugs first, versus "top-down," which gives people stronger drugs earlier in the treatment process.
Ulcerative colitis only affects the colon (large intestine), while Crohn’s disease can affect all of the digestive system, from the mouth to the anus.
It’s sometimes difficult to tell the difference between the two main types of IBD. If this is the case, it’s known as indeterminate colitis.There are other, less common types of IBD called collagenous colitis and lymphocytic colitis. The inflammation can only be seen using a microscope, and so they’re known as microscopic colitis.