Improving quality of colonoscopy by adding simethicone to sodium phosphate bowel preparation

Table 1 Inclusion and exclusion criteria

Inclusion criteria

Adults aged 18-70 years of age scheduled for colonoscopy at the gastroenterological unit

Exclusion criteria

Renal insufficiency (Cr ≥ 2 mg/dL)

Uncontrolled congestive heart failure (NYHC III-IV)

Massive ascites

Myocardial infarction within 6 mo

Pregnancy

Coagulopathy

History of colonic surgery

Colonic obstruction

History of anti-flatulence and/or other laxative agent use within 1 wk

Refusal to participate in the study

Table 2 Baseline characteristics of the study groups (%)

Characteristics	Simethicone	Placebo
	n= 62	n= 60
Age (yr); mean (SD)	57.5 (9.9)	56.5 (11.7)
Gender
Male	27 (43.5)	23 (37.1)
Female	35 (56.6)	37 (61.7)
Indication for colonoscopy
Screening	25 (40.3)	26 (43.3)
Symptomatic	37 (59.7)	34 (56.7)
Underlying diseases
Diabetic	14 (22.6)	12 (20.0)
Hypertension	17 (27.4)	16 (26.7)
Coronary artery disease	2 (3.2)	3 (5.0)
Liver disease	10 (16.1)	5 (8.3)
Malignancy	5 (8.1)	8 (13.3)
GI disease	7 (11.3)	3 (5.0)
No underlying disease	18 (29.0)	22 (36.7)
Medication
Antihypertensive agent	19 (30.7)	20 (33.3)
Hypoglycemic agent	12 (19.4)	11 (18.3)
Antiplatelet	4 (6.5)	7 (11.7)
No medication	25 (40.3)	27 (45.0)

Table 3 Colonoscopic results, endoscopic visibility and procedure time between the study groups (%)

	Simethicone	Placebo
	n = 61	n = 59
Endoscopic findings
Normal	17 (27.4)	16 (26.7)
Polyps	31 (50.0)	28 (46.7)
Cancer	1 (1.6)	3 (5)
Colitis	4 (6.5)	7 (11.7)
Nonspecific	2 (3.2)	2 (3.3)
Others	7 (11.3)	4 (6.7)
Degree of air bubbles
Acceptable	61 (100.0)	25 (42.4)b
Cecum	60 (98.4)	38 (64.4)b
Ascending colon	59 (96.7)	32 (54.2)b
Transverse colon	60 (98.4)	30 (50.8)b
Descending colon	59 (96.7)	30 (50.8)b
Rectosigmoid colon	61 (100.0)	46 (78.0)b
Unacceptable	0	34 (57.6)
Adequacy of colon preparation
Acceptable	55 (90.2)	48 (81.4)
Unacceptable	6 (9.8)	11 (18.6)
Duration of colonoscopy (min); mean (SD)	25.1 (13.2)	27.3 (13.0)

^bP < 0.0001.

Table 4 Endoscopist and patient satisfaction for bowel preparation (%)

	Simethicone	Placebo
	n = 61	n = 59
Endoscopist satisfaction
Air bubble	48 (79.0)	19 (32.8)a
Adequacy of colon preparation	42 (68.9)	33 (55.9)
Patient satisfaction; mean (SD)	8.7 (1.8)	7.6 (1.9)b

^aP < 0.0001,

^bP = 0.002.

Table 5 Side effects of bowel preparation (%)

Symptoms	Simethicone	Placebo
	n = 40	n= 43
Nausea and vomiting	12 (30.0)	16 (37.2)
Abdominal pain	5 (12.5)	6 (14.0)
Fatigue	2 (5.0)	1 (2.3)
Sleep disturbance	0	1 (2.3)