Please select the eligibility criteria that correspond to the clinical trial below.
Title: Comparing Air Insufflation, Water Immersion and Water Exchange Methods During Minimal Sedated Colonoscopy, a Randomized, Controlled Trial
Brief Summary: In minimally sedated Asian patients in a community setting the investigators showed that a limited volume of water infusion instead of air insufflation in either the rectal sigmoid colon or the whole colon significantly reduced pain score during colonoscopy. Cecal intubation rate was not compromised. The reduction of pain score ranges from 25% to 32 % in our previous studies.1, 2 In contrast, several US reports described the successful use larger volumes of water infused throughout the entire colon in patients undergoing colonoscopy which result in a greater reduction of the pain score, averaging about 56%.3-5 A recent review suggested that the cause of the difference might lies in the timing of water removal.6 Specifically, the investigators group removed the infused water predominantly during withdrawal phase (water immersion) and the U.S. group removed water during insertion phase (water exchange).

This prospective, randomized controlled trial compared water exchange or water immersion with traditional air insufflation in patients undergoing minimally sedated colonoscopy. The investigators test the hypothesis that water exchange can reduce more pain than water immersion in the investigators clinical setting.


Options:
A: Inclusion Criteria

* adult outpatients willing to undergo colonoscopy without routine initial sedation

Exclusion Criteria:

* refuse to initiate colonoscopy without routine sedation
* inadequate bowel preparation
* incapacity to give informed consent
B: Inclusion Criteria:

* Adult male and female
* Adult patients 18 years old in need of colonoscopy for screening or follow up of colonic polyps, and willing to consent to be randomized.

Exclusion Criteria:

* Patients receiving outpatient prescription narcotic treatment \[more likely to have discomfort response even with sedation (42)\].
* Patients who report excessive anxiety \[pre-endoscopy appointment, single question asking how anxious the patient generally is, four point scale (1 = not at all, 2 = slightly, 3 = moderately, 4 = excessively\].
* Excessive anxiety is significantly correlated with lack of cooperation during colonoscopy and high dissatisfaction score after the procedure (43).
* Patients with moderate to severe abdominal discomfort, unable to provide informed consent, have a poor bowel preparation (discolored rectal output or feces filled rectal vault), and those who decline to participate, will also be excluded.
C: Inclusion Criteria:

* presentation for colonoscopy
* male
* age 18 or older

Exclusion Criteria:

* women
* known inflammatory bowel disease
* presentation for emergency colonoscopy
* history of partial colectomy
* chronic narcotic or benzodiazepine use
D: Inclusion Criteria:

* Patients undergoing minimally sedated colonoscopy

Exclusion Criteria:

* Obstructive lesions of the colon, inadequate bowel preparation, allergy to meperidine, massive ascites, past history of partial colectomy, or refusal to provide written informed consent.

Answer: D