In terms of pregnancy, the Food and Drug Administration labels drugs and medications with letters A,B,C,D. Class “C” drugs are considered to be mostly safe, but should be taken under the care of a health care provider. Class “D” drugs have great risks. Pepto Bismol is considered a class “C” medication for the first and second trimesters and class “D” for the third trimester. You should always consult with your health care provider before taking Pepto Bismol while you are pregnant. Imodium is a better choice during pregnancy, as it is a class “B” drug for all three trimesters. While still classified as safer, it is highly recommended that you contact your doctor before ingesting any medications while you are pregnant.