I give the child 2x5 ml of the antibiotic Taromentin. A 70 ml bottle should be enough for 14 doses, and I ended up with 11. Did I add too little water, or did so much settle on the walls of the bottle?

According to the dosage, you should get 14 doses from a properly prepared suspension (14x5 ml = 70 ml). In this situation, it is more likely that too little water was used to make the medicine. Even if part of the suspension has been retained on the walls of the bottle, it should not be such a large amount. (This "behavior" of the drug in the bottle could be classified as a quality defect.) The residue of the suspension in the syringe is irrelevant here, because the amount withdrawn from the bottle into the syringe is still 5 ml. ("Leftovers" in the syringe only reduce the dose administered once). According to the information contained in the leaflet, to obtain 70 ml of suspension to the bottle, add 62 ml of water - to the level of the line marked on the label, shake and after leaving to make up the missing amount of water to the level of the line (if necessary). If the antibiotic was missing on the 6th day of use, it is advisable to contact a doctor. This duration of therapy may be sufficient to fight the infection, but your doctor may also recommend continuing therapy for 7-10 days. Prescription drugs can be booked at the pharmacy of your choice via the GdziePoLek portal: https://www.gdziepolek.pl/produkty/77472/taromentin-400-mg-57-mg-proszek-do-wytworzenia-zawiesiny/apteki