The purpose of this randomized study is to compare ESD procedural time and cost facilitated with a dual balloon accessory device versus ESD procedures performed without the accessory device. Study is designed to detect if the double balloon interventional platform helps to perform removal of benign complex colonic lesions safer and in more efficient way.

This is a prospective, post-market, randomized clinical trial comparing colonic ESD procedures utilizing the DiLumen™ Endolumenal Interventional Platform to colonic ESD procedures that are performed without use the DiLumen™ device.

The study participants will be randomly assigned to study group and control group The treatment group will consist of up to 100 subjects treated with the DiLumen™ device. The control group will consist of up to 100 subjects treated without DiLumen™ device. Assessments will include procedure timepoints, anesthesia use, polyp location and classification, over-all cost assessment, and general complications.

The primary outcome will be analyzed using parametric statistics to compare the means of the study and control groups. P-values and confidence intervals will be reported. Descriptive and summary statistics will also be employed. Secondary outcomes will be summarized with descriptive statistics.

Inclusion Criteria:

1. Men or women 18-85 years of age.
2. Have ability to understand the requirements of the study and provide written informed consent
3. Suspected complex adenomatous polyps in the large intestine defined as sessile or polypoid lesions 2 cm and larger in size.
4. No medical contraindication to endoscopic submucosal dissection (ESD).

Exclusion Criteria:

1. Contraindication to colonoscopy, such as active colitis, diverticulitis, perforation, or stricture.
2. History of open or laparoscopic colorectal surgery.
3. History of Inflammatory Bowel Disease (IBD).
4. Any medical or surgical condition that would preclude the endoscopic removal of the polyp.
5. Anatomy or other factors that prohibit safe access to the large intestine such as previous radiation therapy to the affected area, known colonic strictures, extensive colonic diverticuli, etc.
6. History of AIDS, HIV, or active hepatitis.
7. History of mental illness, including psychological or neurological conditions (addiction to substances such as alcohol. e.g.) that in the investigator's opinion would pre-empt their ability or willingness to participate in the study.
8. Patients who are pregnant or lactating.
9. Currently involved in another investigational product for similar purposes.

Study records should be stored in a secure area to limit access to study personnel and maintain confidentiality of the records.

The patients will be randomly assigned to study or control group. The patients will not know their assignment until completion of the study.