Can you develop lactose intolerance?

I became lactose intolerant at 19 so yes it is possible. Definitely talk to your doctor, there is a test you can get to know for sure.

Edit: If you have the opportunity try to eliminate lactose for a couple weeks and see if that helps. I know for me I have to eliminate all dairy, even 99% lactose free still bugs me. I found an almond milk yogurt that is good as well as cashew milk ice cream that really hits the spot!

Yes you can. Only certain things bother me too. I can do a moderate amount of cheese and cottage cheese. But milk and yogurt can make my stomach very unhappy.

Yup, you can both grow into, and grow out of, lactose intolerance and all sorts of other intolerances/allergies.

My daughter became lactose intolerant and developed shellfish allergies in her late teens. Never had either before.

Yes. Things come and go throughout life. Unfortunately more seem to come than go, lol! Just cut out the things that bother you most and you'll probably be fine.

Yes, most babies are not born lactose intolerant, people become lactose intolerant later in life.

This is the new sucky thing that's going on with me. I used to have a full 8oz of milk in my morning smoothie and a few weeks ago it started disagreeing with me, so I subbed the milk with water and half a banana for creaminess.

Thought it was a fluke and went back to milk yesterday and regretted it as my stomach gurgled all day

My lactose intolerance started kicking in a few years ago, but it's pretty much limited to drinkable quantities of milk. Ice cream sometimes triggers it, but cheese, yogurt, and buttermilk don't appear to bug me at all. Interestingly, since I've started eating a lot of Greek yogurt the intolerance seems to have backed off a little bit.

Yes, I am and only since adulthood. Some of those items have minimal lactose (butter, for the amount you eat on a potato). IBS however can be flared by chocolate, oats, etc. It might be beneficial to look into a low-fodmap diet. You go through elimination diet and then introduce items slowly. Fodmaps are basically short chain carbohydrates that cause gas in the intestines, bloating, etc There is a (for a fee) app that is great called Monash I think to help if needed.

I developed lactose intolerance after a back to back episode of malaria and typhoid when I was 14 yrs old

I'd second attempting to cut out all dairy and see how you do. Because as everyone has said, yeah, it can happen at any time. Although, to note, lactose intolerance can occur due to damage of the intestines in the area where lactase is made. So sometimes, severe stomach bugs or food poisoning can cause temporary lactose intolerance. This is also something common with the damage from celiac disease, and a few celiacs I've known had lactose intolerance as one of the first signs of their disease (so if you start having problems with any wheat products, too, you should probably check into that - the treatment for it involves a dietary change, but no meds, so not super expensive for those of us in the non-insurance train).

For when you add it back in, IF lactose seems to be the problem, you'll want to do a little research on the dairy, because the lists on what is safe, and what is not, don't always agree with each other, or with people's experiences, and this is why.

The dairy that you can eat is the dairy where the lactose is no longer present, or present in very small amounts. When lactose ferments, the bacteria doing the fermenting EAT the lactose. So any product that is allowed to go through this process all the way, like buttermilk, or yogurt, has little to no lactose. Aged, harder cheeses have the lactose containing whey drained off, and the aging helps convert most of the rest to lactic acid. butter that has been clarified, like ghee, as the milk solids containing the lactose mostly removed. So you would think that would help figure it out, yeah?

The only problem is that modern manufacturing has completely bejanked the whole process, mostly in the USA. It takes time to ferment foods, so instead of letting dairy fully ferment, many American companies will allow yogurt/buttermilk to partially ferment only, and then they add in souring agents or thickeners to 'fake' the taste and feel of a fully fermented dairy product. So the product still has plenty of lactose in it. In fact, sometimes the thickener is MORE dairy, so the product can have more lactose than it started out with!

Cheeses can also have issues like this, but less often.

One interesting take on how to see if a dairy food has lactose or not is to look at the sugars, though - this article talks about it: https://lifehacker.com/the-best-cheeses-to-eat-if-youre-lactose-intolerant-1563386663