Hi, thanks for asking in Healthcare Magic. Most common causes of diarrhea are amebiasis and bacterial infection. But unfortunately almost all the conventional anti amebics (drugs used in amebiasis) and most of the antibiotics are harmful to the fetus. Since well being of the baby is the top priority during a pregnancy only natural remedies are preferred to control the infection in mother. Severe abdominal cramps due to diarrhea can cause abortion. Drugs are given only when the diarrhea is severe under the supervision of physicians. Stool examination should be done to confirm the type of infection before selecting the drug. Amoxycillin is safer among antibiotics for bacterial diarrhea. The anti amebic Metronidazole is absolutely contraindicated during first semester. However Probiotics like Lactobacillus can be used with caution in both infections during pregnancy. Preventing dehydration is the most vital aspect of treatment in any type of diarrhea. Take oral rehydration fluids (ORS) like Electral. If dehydration is severe, then you will need IV fluids. Bland diet like whole bread toast, rice and bananas will control diarrhea. Fresh fruits like apples, butter milk or yogurt are preferable. I hope this is useful to you.