The symptoms of stomach discomfort after taking birth control pills is a relatively common adverse reaction to birth control pills. Because the main ingredient of the pill is progestin or a combination of estrogen and progestin, it may cause obvious gastrointestinal reactions after taking it, mainly manifested as nausea, vomiting, abdominal pain, bloating, loss of appetite, etc. Such reactions usually appear within 24 hours after taking the pill, and will be relieved or stopped on their own after 24 hours. When taking the pill, try to take the pill at night before going to bed, which can effectively relieve the symptoms of adverse reactions. If the stomach discomfort persists without relief, or even gradually worsens, perhaps it is not related to the pill, you should go to the hospital for examination for further diagnosis.