Appropriateness of colonoscopy: Diagnostic yield and safety in guidelines

Table 1 ASGE and SIED selection criteria for colonoscopies

ASGE	SIED
Abnormality on barium enema	Abnormality on barium enema, 1Computerized Tomography scan, Magnetic Resonance Imaging, Ultrasonography
Haematochezia–Fecal occult blood test positivity–melena after negative upper GI endoscopy	Haematochezia–Fecal occult blood test positivity-Melena after negative upper GI endoscopy
Unexplained iron deficiency anemia	Unexplained iron deficiency anemia
Surveillance for colonic neoplasia and colonic polyps	Surveillance for colonic neoplasia and colonic polyps
Clinically significant diarrhea of unexplained origin	1Persistent and significant alterations of bowel habits
Surveillance of inflammatory bowel diseases patients	Surveillance of inflammatory bowel diseases patients
Evaluation of inflammatory bowel diseases of colon when colonoscopy will influence immediate management	Evaluation of inflammatory bowel diseases of colon when colonoscopy will influence immediate management
Chronic abdominal pain: once to rule out disease	Chronic abdominal pain: once to rule out disease
	1Unexplained weight loss

¹Different criteria between ASGE and SIED guidelines.

Table 2 921 indications in 866 appropriate colonoscopies

ASGE/SIED guidelines	n	%
Haematochezia	218	23.7
Occult faecal blood presence	154	16.7
Surveillance after endoscopic polypectomy	136	14.7
(3-5 yr intervals following adequate clearance of neoplastic polyps)
Persistent change in bowel habits	105	11.4
Surveillance after resection of cancer	100	10.8
(colonoscopy to remove synchronous neoplastic lesion at or around time of curative resection of cancer followed by colonoscopy at 3 yr and 3-5 yr thereafter to detect metachronous cancer)
Chronic abdominal pain	57	6.2
Unexplained iron deficiency anemia	54	5.9
Family history of sporadic colorectal cancer before the age of 60: colonoscopy every 5 yr beginning at the age of 10 yr earlier than the affected relative or every 3 yr if adenoma is found	42	4.6
Abnormality on imaging	28	3.0
Unexplained weight loss	18	1.9
Chronic inflammatory bowel disease of colon, if more precise diagnosis or determination of the extent of activity of disease will influence immediate management	9	1.0
In patients with ulcerative or Crohn’s pancolitis ≥ 8 yr or left sided colitis ≥ 15 yr every 1-2 yr with systematic biopsies to detect dysplasia

Table 3 Indications in 151 inappropriate colonoscopies

Indications	n	%
Surveillance of colonic polyps out of recommended intervals (3-5 yr intervals following adequate clearance of neoplastic polyps)	49	32.4
Transitory or already endoscopically investigated unmodified chronic abdominal pain	30	19.9
Transitory change in bowel habit	21	13.9
Colorectal carcinoma surveillance out of guidelines (colonoscopy to remove synchronous neoplastic lesion at or around time of curative resection of cancer followed by colonoscopy at 3 yr and 3-5 yr thereafter to detect metachronous cancer)	20	13.2
Melena with upper gastrointestinal source already identified	9	6.0
Screening in patients with family histories of sporadic colorectal cancer before age of 60 out of guidelines (colonoscopy every 5 yr beginning at the age of 10 yr earlier than the affected relative or every 3 yr if adenoma is found)	6	4.0
Hematochezia in patients < 40 yr without previous rectal evaluation	4	2.6
Follow-up for inflammatory bowel diseases out of recommended intervals. Chronic inflammatory bowel disease of the colon, if more precise diagnosis or determination of the extent of activity of disease will influence immediate management	3	2.0
In patients with ulcerative or Crohn’s pancolitis ≥ 8 yr or left sided colitis ≥ 15 yr every 1-2 yr with systematic biopsies to detect dysplasia
Anal symptoms	3	2.0
Rectal incontinence	2	1.3
Abnormal serologic markers (CEA, carcino Embriogenic Antigen, Cancer Antigen 19-9)	2	1.3
Metastatic adenocarcinoma of unknown origin without colonic symptoms when it will not influence management	1	0.7
Inguinal hernia	1	0.7

Table 4 Pathologic findings in appropriate colonoscopies

Pathologic findings	866 appropriate		151 inappropriate
	n	%	n	%
Low grade dysplasia adenoma	92	41.8	9	6.0
Colorectal cancer	71	32.3	-	-
Undetermined polyps (unretrieved polyps size < 5 mm)	25	11.0	5	3.3
High grade dysplasia adenoma	25	11.4	2	1.3
Inflammatory bowel diseases	17	7.7	-	-
In situ adenocarcinoma	3	1.4	-	-
	233	26.9	16	10.6