Please select the eligibility criteria that correspond to the clinical trial below.
Title: Water Colonoscopy Versus Air Colonoscopy for Unsedated Patients With Prior Abdominal or Pelvic Surgery: a Prospective Randomized, Controlled Trial
Brief Summary: Water method with water exchange has been shown to reduce medication requirement and pain experienced during colonoscopy. It increases the success rate of cecal intubation in sedated and unsedated patients undergoing screening colonoscopy. Exchange of water during scope insertion minimizes distension of the colonic lumen and decreases loop formation. Exclusion of air from the colon during insertion by omission of air insufflations and suction removal of residual air prevent elongation of the colon. These maneuvers facilitate colonoscopy insertion in average patients and may enhance the success of difficult colonoscopy.

Prior abdominal or pelvic surgery is an independent factor for difficult colonoscopy, the probable adhesion may change the anatomy and increase the discomfort of patients. We postulate that these patients may benefit from using the water method for colonoscopy. In this proposal we test the hypothesis that compared with conventional air insufflations the water method with water exchange significantly enhances the success rate of cecal intubation in patients with prior abdominal or pelvic surgery.

The aim of the study is to compare the outcome of colonoscopy using the water method versus the conventional air method in patients with prior abdominal or pelvic surgery. The primary outcome is cecal intubation success rate. The secondary outcomes include cecal intubation time, maximum pain score during colonoscopy, overall pain score after colonoscopy and adenoma detection rate.


Options:
A: Inclusion Criteria:

* Adult (\> 50 years old), male and female patients
* Scheduled and consented for screening or surveillance colonoscopy
* Accept randomization to the study or the conventional method
* Agree to complete study questionnaires will be considered for enrollment
* Normal healthy patients or patients with mild systemic disease, ASA 1 or ASA 2

Exclusion Criteria:

* Patients who decline to participate, are unable to give informed consent or to complete the questionnaires due to language or other difficulties will be excluded. Excluded patients will be managed by usual procedures at the Sacramento VAMC
B: 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.
C: Inclusion Criteria:

* Patients with prior abdominal or pelvic surgery,

Exclusion Criteria:

* History of colorectal surgery
* Severe colonic stricture or obstructing tumor
* Patients who cannot give informed consent and those who are hemodynamically unstable
D: 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.

Answer: C