Finding Baby Products

Planning a family trip is not just about booking tickets, booking accomodation, making sure everyone has valid passports, everyone is properly immunized, any required visas are in place, that you have enough money (cash or otherwise) to last the entire trip, that you know how to get around (and have a rental car if you need to), and so on.
With small children, you need to buy products that adults typically do not require (like diapers and formula), and you need to be prepared for medical emergencies that would not matterto an adult. On the other hand, infants do not have dental emergencies (since they have no teeth).
But this means you either have to be able to read the local language, or check in advance what baby products are available. And if you are price sensitive, you need to know the word for the product you are looking for. A picture of a smiling baby on the package does not necessarily mean that it is the kind of product you are looking for. And even when there is some text in English, you may need more background. Is "big" diapers bigger than "large"? In which dimension? And will they last through the night?
If you do have some local knowledge, you can make bargains. I once bought 50 packs of Tesco diapers, because they were marked down to 10% of the original price at the bargain corner at Tesco Lotus at On Nut, where you would otherwise only find packages of cereal picked open by the birds, dented cans, and similar. They lasted all of three weeks.
Local language is useful in other ways. Trying to ask the staff in the formula aisle of the same Tesco Lotus which products were hypoallergenic and suitable for 3 to 6 months old kids without knowing more than the Thai words for "diapers" was a challenge, but they got the idea after I performed a little pantomime illustrating the kids being born and counting days, although we never could agree on what I meant with the puking bellyache pantomime. The New Zealand goats milk based formula we eventually agreed on because I could read some of the text on the can was quite effective although the kids did smell funny for a while, until we got a shipment of more advanced products from Japan.
And this assumes you even know where in the store, and which store you are looking for. When it comes to everyday baby goods you can easily find them in most grocery stores, but you do not even have to go into specialist products like goats milk based formula to be limited to specialized stores. And those can be really hard to find. Or you may find that products you are looking for are only sold by the pharmacies in the country you are visiting, contrary to your home country.
That means the challenge is not just the location, but the opening times. Pharmacies in many countries have worse opening hours than government agencies, and are stuffier than banks. You need to visit in the few minutes that they are open to get that medication you find would make your child breathe easier. And cross your heart to hope that the English-speaking pharmacist is working that day. If you need to communicate that you need a special kind of medication, you can be Marcel Marceau and your pantomime will still leave the clerk scratching her head. If you have written down the name it nerds to be in the local writing, because in countries that use other forms of writing than the alphabet, people can not necessarily read the alphabet unless they have been to university. Which pharmacists have. But not clerks. Even young people who may have studied English in school may not be as proficient as you would expect.
You can go to the international chains, but even at Boots in Thailand the English proficiency is leaves a lot to wish for. They may carry international brands, but if the text on the bottle is in Malay if it is not in Thai, you do not know if what you are buying is shampoo or conditioner. International brands are no guarantee for recognizability. Even more so in southeast Asia, where the brands are Japanese or Australian, or Malaysian.
The challenges at the time and the worries you feel for your kids - and the relief you feel when they fall peacefully asleep in their new diapers - is part of why you will look back so fondly on this particular trip. It may be extremely painful when you experience it, but the stories you are going to tell will last for a long time. Much longer than your kids diapers.