Table 1.

Differential diagnosis in older individuals

Differential diagnosis	Symptoms that may mimic	Points to aid differential
Infectious	Diarrhoea, blood, weight loss	Recent travel; new medication, especially antibiotics
Ischaemic colitis	Bloody diarrhoea, abdominal pain usually sudden onset, pain associated after food	Cardiovascular disease Peripheral vascular disease Diabetes, hypertension, hypercholesterolaemia Smoker, arrhythmias
Diverticular disease	Left-sided abdominal pain, bloody diarrhoea	Classic left-sided pain Colonoscopic/radiological evidence Segmental colitis associated with diverticulitis Segmental peridiverticular distribution with rectum and proximal colon spared
Microscopic colitis	Diarrhoea	Drugs that may contribute non-steroidal anti-inflammatory drugs, lansoprazole, SSRIs Normal macroscopic findings
Radiation-induced colitis	Bloody diarrhoea	Previous radiotherapy
Solitary rectal ulcer	Rectal bleeding, tenesmus	History of chronic constipation with straining
Colorectal cancer	Change in bowel habit, rectal bleeding, weight loss	Systemic features, weight loss
Pancreatic insufficiency	Diarrhoea, weight loss	Floating, pale, foul-smelling stools

SSRI, selective serotonin reuptake inhibitors.