Investigations

^{Iron-deficiency anaemia}

• Gastroscopy and colonoscopy or barium enema/sigmoidoscopy ^c  

Why?

• Failure to investigate upper and lower bowel misses important lesions: 16% of elderly patients with benign upper GI lesions had colonic carcinoma or adenomas in one series.
• Colonoscopy is a better test than sigmoidoscopy followed by barium enema in patients with suspected large bowel disease- there are more complete examinations and few additional investigations but no clear difference in the number of diagnoses made nor patient satisfaction. ^a

Colonoscopy leads to a more complete examination and few further investigations

Patient	Treatment	Comparison	Outcome	CER	RRR (95% CI)	NNT (95% CI)
suspected large bowel disease a	colonoscopy	sigmoidoscopy and barium enema	complete examination at	36%	87% (36% to 100%)	3 (2 to 6)
suspected large bowel disease	colonoscopy	sigmoidoscopy and barium enema	further investigation required at	27%	72% (35% to 88%)	5 (3 to 12)