From the Guidelines

Managing Plavix (clopidogrel) for colonoscopy is generally safe for polyps <1 cm in size on clopidogrel monotherapy, but caution is advised.

The risk of post-polypectomy bleeding (PPB) is increased with continued clopidogrel use, but the overall risk is still relatively low [ 1 ].
Cold snare polypectomy may be advisable to minimize the risk of PPB [ 1 ].
Temporarily substituting aspirin for clopidogrel 7 days prior to colonoscopy may be desirable [ 1 ].
For high-risk endoscopic procedures, discontinuing clopidogrel 5-7 days before the procedure is recommended, especially in patients at low thrombotic risk [ 1, 1 ].
In patients at high thrombotic risk, continuing aspirin and liaising with a cardiologist about the risk/benefit of discontinuing clopidogrel is recommended [ 1, 1 ].

For diagnostic procedures or low-risk procedures, continuing clopidogrel may be acceptable [ 1 ].
For high-risk procedures such as endoscopic polypectomy, ERCP with sphincterotomy, or endoscopic mucosal resection, discontinuing clopidogrel 5-7 days before the procedure is recommended [ 1 ].

Patients with a history of ischemic heart disease, cerebrovascular disease, or peripheral vascular disease may require closer monitoring and consultation with a cardiologist [ 1 ].
Patients with a high risk of thrombotic events may require continued antiplatelet therapy, and the decision to discontinue clopidogrel should be made on a case-by-case basis [ 1, 1 ].

From the Research

The management of Plavix (clopidogrel) for colonoscopy is a complex issue, with current guidelines recommending the cessation of clopidogrel therapy 5-7 days prior to colonoscopic polypectomy 2.
However, recent studies have suggested that continued clopidogrel therapy may not significantly increase the risk of post-polypectomy bleeding (PPB) 3, 4.
A meta-analysis of five observational studies found that the pooled relative risk ratio (RR) of colonoscopic PPB in patients on continued clopidogrel therapy was 2.54 (95% CI 1.68-3.84, P < 0.00001) 2.
Another study found that the delayed PPB rate for patients on clopidogrel was less than 1%, and PPB rates did not differ significantly between users and non-users 3.
A randomized controlled trial found that the cumulative incidence of delayed postpolypectomy bleeding was 3.8% in the clopidogrel group and 3.6% in the placebo group (P = .945) 4.
A systematic review and meta-analysis found that there was an increased risk of PPB with continued clopidogrel (P=0.0003; risk ratio (RR), 1.96; 95% confidence interval (CI), 1.36-2.83) 5.

Endoscopists should be cognisant of the risks and benefits of continued clopidogrel therapy during colonoscopy and consider deferring elective colonoscopy and polypectomy until it is considered safe to interrupt clopidogrel therapy 2.
Cold snare polypectomy and endoscopic clipping may be used to manage intraprocedural bleeding and make routine colonoscopy on continued antiplatelet agents safe 6.
The decision to continue or interrupt clopidogrel therapy should be made on a case-by-case basis, taking into account the individual patient's risk of thrombotic events and bleeding complications 5.