It's not that steel pellets would go flying out your guts. More that there have been cases in USA, one where an individual had steel alloy pellets remaining for months in his guts. As well as bowel cancer. Trying to do an MRI of the cancer was impossible. If they were lead, this would not if been such an issue on imaging as they would not interfere with the magnetic resonance image!The gut is not a problem hence my response.
Denmark have been using steel shot exclusively for 20 years.... maybe they don't have MRI scans.........
Chances are low of this happening. But then again I have not read of countless cases of folk suffering from lead poisoning from lead pellets. HSE and others should look at other areas of industry where the use of lead causes more frequent and harmful health issues. But they are not because there is money in those areas and they are not so easy targets. Again for myself I am happy to shoot steel. But the cost of replacement barrels and ammunition needs to come more affordable for both shotgun and rifle users, if the shooting community in UK is to continue and allow generations to continue.