Final answer:
Both amoxicillin and ampicillin can cause diarrhea by disrupting the gut's bacterial flora, with no significant difference in the incidence of diarrhea between the two. Oral probiotics may help reduce antibiotic-associated diarrhea.
Step-by-step explanation:
When comparing amoxicillin and ampicillin, both are penicillin derivatives and are known to cause diarrhea as a side effect due to the disruption of normal bacterial flora in the gut. However, there is not a significant difference in the likelihood of causing diarrhea between these two antibiotics for most patients. Diarrhea can be a common side effect of many antibiotics, including both amoxicillin and ampicillin, because they can kill off the "good" bacteria in the gut responsible for aiding in digestion. This disruption can allow harmful bacteria, like Clostridium difficile, to increase in number, leading to symptoms such as diarrhea. Additionally, the use of oral probiotics may reduce the incidence of antibiotic-associated diarrhea.