Not an expert, baz, but it's different for different conditions. It's harsh on the stomach and can cause bleeding. My son was checked with it in hospital, as he was asthmatic and it can bring on asthma (broken leg). Most painkillers are metabolised by liver, so a problem there, could mean overdose. It really varies, as to what the issue is.
Yes.....the main risk is bleeding from the intestinal tract or stomach and if you are an asthmatic to tread carefully with Ibuprofen. In my opinion both overstated .
Take Ibuprofen either with water or with a meal.
I take medication for high blood pressure which apparently dilates the blood vessels to lower the pressure. As an anti-inflammatory ibruprofen does the opposite, hence counteracting the medication.
I had shoulder and neck pain once and the doctor prescribed strong ibuprofen tablets. When I queried
it she told me it was ok, and was only a problem if taken long term. I only took them for a couple of days.
Asthma, allergies and the like are known to cause a number of issues with several medications, and unless you have some way to treat asthma, you're out of luck.
Probably your best shot if you're really having trouble is to contact a professional online who's known to treat your issue.