Radiation proctitis differential diagnosis

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief:

Overview

Radiation proctitis must be differentiated from infectious colitis,inflammatory bowel disease,ischemic colitis,medication-associated colitis,chemical colitis and allergic colitis

Differentiating Radiation proctitis from other Diseases

The following conditions may present in a similar manner as radiation proctitis, and should be excluded:

• infectious colitis,
• inflammatory bowel disease,
• ischemic colitis,
• medication-associated colitis
• chemical colitis
• allergic colitis

The table below lists the differential diagnosis of common causes of colitis:

Diseases	History and Symptoms					Physical Examination				Laboratory findings
	Diarrhea	Rectal bleeding	Abdominal pain	Radiation exposure	Atopy	Dehydration	Fever	Hypotension	Malnutrition	Blood in stool (frank or occult)	Microorganism in stool	Imaging	Pseudomembranes on endoscopy
Allergic Colitis	+	++	+		++					++
Chemical colitis	+	++	++			+	+			++			+
Infectious colitis	++	++	++			+++	+++	++	+	++	++	CT shows bowel wall thickening and edema	+
Radiation proctitis	+	++	+	++		+			+	++
Ischemic colitis	+	+	++			+	+	+	+	++		Abdomen xray shows distention and pneumonitis CT scan suggestive of double halo appearance and thumb printing sign
Inflammatory bowel disease	++	++	Diffuse +			+/-	+/-		+	++		String sign on abdominal xray in Crohn's
Medication induced colitis	+	+	++				+			++			+