Hi! Thanks for your question on the forum. 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 is one among them. Also beer 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. Beer 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
let me know if there is any thing else and do keep me posted. Take care!