Acute diarrhea, a common gastrointestinal disturbance, is characterized by the rapid evacuation of fluid stools, leading to an excessive weight in fluid. This condition typically arises from disorders affecting intestinal water and electrolyte transport. It can be triggered by an increased osmotic load within the intestine, excessive secretion of electrolytes and water, mucosal exudation of protein and fluid, or altered intestinal motility. The primary risks of acute diarrhea are dehydration and electrolyte imbalances, which necessitate prompt medical attention.

Traveler's diarrhea is a frequent health concern among individuals traveling across international borders. Typically, it is caused by the enterotoxin-producing bacteria Escherichia coli (E. coli) or other similar organisms. While most cases are mild and self-limiting, requiring only oral fluid and salt replacement, severe or persistent symptoms may require empiric antibiotic therapy. Other bacteria, such as Campylobacter spp., Salmonella, and Shigella, and protozoa like Giardia and Cryptosporidium spp., are also responsible for causing diarrhea.

Fluoroquinolones and azithromycin are the first-line therapy for traveler's diarrhea, with other possible therapies including ciprofloxacin, norfloxacin, ofloxacin, and levofloxacin. These antibiotics target bacterial DNA gyrase and topoisomerase IV, inhibiting gyrase-mediated DNA supercoiling, a process vital for bacterial growth. The dosage regimens for these drugs usually range from once to twice daily for up to 3 days.

Other therapeutic agents, such as rifaximin and trimethoprim/sulfamethoxazole, are alternative antibiotics used to treat traveler's diarrhea if the therapies listed above are ineffective or inadvisable. For children, azithromycin is the preferred treatment. The recommended dosage is 10 mg/kg, up to a maximum of 500 mg single dose.