I ask this as our gracie has such a delicate tummy. She came to us at 7 weeks old ! Was sick after eating most commercial cat foods and took us weeks until we found a particular brand of vetinary food she could eat ! I can tell when she is constipated as she just sits there and looks unhappy ! She's an indoor cat and we do open the kitchen door and she just sits at the door looking out and I always say to her 'how an earth would you survive out there with your tummy ?' Well yesterday not only did she fall into a sink of soapy water when she was being nosey to see what I was cooking, but she took a bit of roast chicken soaked in spices and gravey from the side ! Well after this she spent all night sat under the clothes rack, staring at us as we slept ( she usually sleeps with us) she looked so unhappy and very unwell and didn't eat or seem interested in us or anything ! She usually follows us around the house however just stayed under the clothes rack ! We took her to the vets and he advised thought the herbs had upset her and 3 injections later and a diet of boiled chicken she's getting back to her old self! So as my question : how an earth do stray and outdoor cats survive ? They must eat all sorts !