Diarrhoea after antibiotics: what to know

Antibiotics can change the balance of microbes in the bowel, leading to loose stools, cramping, or urgency during treatment or after the course ends. Sometimes a different infection takes advantage of that disruption and causes more marked diarrhea. The antibiotic name, start date, dose changes, and the interval between the last tablet and symptoms help a clinician judge the pattern. Diarrhea can also be unrelated, such as from food poisoning.

Fluid loss can cause thirst, dry mouth, dizziness, tiredness, or less urine. Blood, fever, significant pain, or worsening symptoms need more than simple observation.

Drink small amounts often, using an oral rehydration drink if losses are frequent. Eat gentle foods as tolerated and wash hands with soap after toilet use. Do not stop, restart, or switch the antibiotic without speaking to the prescriber; the original infection may still need treatment. Avoid sharing towels and clean bathroom surfaces if an infectious cause is suspected. Keep the medicine packaging and record stool changes for the consultation.

Seek urgent care for black or bloody stools, severe abdominal pain, fainting, confusion, severe dehydration, or rapidly worsening weakness. Contact a clinician promptly when diarrhea is frequent, continues after the antibiotic, returns after settling, or occurs with fever. They may review the antibiotic, examine you, and arrange stool testing. Do not take an anti-diarrhea medicine without advice when infection is possible.

Could this be a medicine effect or an infection? Should I continue the prescribed course? Do I need stool testing or a different treatment? How can I replace fluids safely?