Under what circumstance is Neomycin used orally?

Neomycin is used orally primarily as a bowel decontaminant, particularly in preparation for surgical procedures involving the gastrointestinal tract. Its role lies in reducing the bacterial load in the intestines, thereby minimizing the risk of postoperative infections and ensuring a cleaner surgical field. This use exploits Neomycin's ability to target and suppress the normal flora of the gut, which can be advantageous before surgeries such as enterostomies or colorectal surgeries.

While Neomycin has broader antibacterial properties, it is not typically used as a general antibiotic due to its toxicity when absorbed into the systemic circulation, making oral administration specific to situations where local gut action is desired, and systemic absorption should be minimized. It does not have analgesic properties and is not employed as a preventative measure in the general sense but rather in specific surgical contexts.