Yes some people do get diarrhea from eating too much cottage cheese.
Also if you're lactose intolerant and eat cottage cheese that can lead to stomach cramps and then possible diarrhea even if you eat just a little bit of the cottage cheese.
Cottage Cheese contains lactose and when you eat too much of that lactose then it can lead to diarrhea and stomach cramps.
Cottage cheese can also give you stomach pain, cause bloating and even give you gas if you eat too much of the cottage cheese or if you're lactose intolerant.
Also if you have previously eaten cottage cheese without developing diarrhea and suddenly are getting stomach cramps and diarrhea from eating cottage cheese then you may be lactose intolerant.
Lactose intolerance can come on later in life so it would be a good idea to get tested.
Eating cottage cheese in moderation is healthy but overdoing the cottage cheese can cause stomach cramps and diarrhea.
So if you're getting diarrhea or stomach cramps when eating cottage cheese then it would be a good idea to cut down on the amount of cottage cheese you're eating.