PEG is the basis of a number of laxatives.[10] Whole bowel irrigation with polyethylene glycol and added electrolytes is used for bowel preparation before surgery or colonoscopy. PEG is also used as an excipient in many pharmaceutical products. When attached to various protein medications, polyethylene glycol allows a slowed clearance of the carried protein from the blood.[11] The possibility that PEG could be used to fuse nerve cells is being explored by researchers studying spinal cord injury.[10]