Interfering with how the medicine is digested and absorbed by the body. For example, milk blocks iron absorption in the stomach. Calcium found in dairy products can bind some medications, such as iron supplements and some antibiotics (Cipro and Levaquin, a quinolone.)
Pros of elongated: much more comfortable for adults. I would definitely choose it for the master bathroom. Pros of round: easier for very young children to use due to the smaller opening in the seat. Also, there are code requirements of how much foot space you need in front of a toilet.
To determine which size toilet you have, and thus which size toilet seat will fit your toilet, grab a measuring tape. Measure the length of the toilet bowl from the hinge post holes to the front rim. If the length is about 16-17 inches, a standard round toilet seat will fit your toilet. If the length is 18-19 inches, an elongated/oblong toilet seat will fit. Both toilet seat sizes have a width of about 14.5 inches, and in the United States, the distance between the hinge post holes is about ...