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Antibiotics are antimicrobial substances, which can be used to kill or inhibit the growth of microorganisms, such as bacteria and fungi. Many useful microbes are found in our body, such as good bacteria found in intestines that help in food digestion.
When we use antibiotics to kill pathogenic bacteria, these antibiotics also kill these good bacteria. This results in improper digestion and causes diarrhea. Thus, diarrhea is a common side effect due to antibiotics as these antibiotics also kill gut microbes that help in digestion.
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