Recently had a bowel scope screening in uk .pain,only tolerated views up to 30cm sigmoid colon didn't reach decending bowel screening will not go further than splenic flexure .offered a re-scope appointment this time with entonox ,safe with asthma?

Entonox: Ananaesthetic gas ( 50% nitrous oxide, 50 % oxygen) is generally safe and commonly used, for light sedation during minor procedures, no known to have complications when used properly, (i.e. not abused) . Having asthma isn't an absolute contraindication to using the drug, however you want to mention that to the doctor / anesthesiologist providing It, best wishes