Hi! Thanks for your question on the forum. Yes you can take alcohol in moderation 24 hours before the
preparation. However once the preparation of the bowel starts you cannot consume any alcohol. The preparation
of bowel at times starts 2-3 days in advance in people who are constipated. Hence if this is the case with you
then you cannot drink alcohol even 24 hours before. Alcohol also causes constipation. What you eat and drink
before a colonoscopy test determines how clear your bowel will be for a successful test. Any colored beverage
is avoided before the test as it may color the mucosa of the colon. Beer and red wine are one among them. Also
alcohol causes dilatation of blood vessels of GI tract and hence may give a false picture of inflammation of
colon. The preparation of bowel involves laxatives to clear the bowel. Hence a person passes frequent stools
and the gut is almost empty. Alcohol can aggravate acidity and loss of fluids and hence cause more harm than
good. Colonoscopy itself causes some drowsiness and loss of fluids. Beer and other alcohols add to this effect
and can be dangerous. Also if due to some reason a general anesthesia may be required, then alcohol of any
kind interferes with the effect of anesthetic drugs. Beer and alcohol also interfere with muscle relaxants and
mild sedatives given during the procedure. Hence for similar reasons alcohol is to be avoided for next 24
hours too after the procedure. Hope this helps. Please feel free to ask anything else you may want to know.
Hope this helps. Take care!