I've had IBS all my adult life and been treated for it. At one time, I was losing 1/2 lb. a week, my food was not digesting at all. How many 1/2 lbs. a week can you lose before you have NO weight?
I was at 108 lbs. My height was 5'5". My doc put me in the hospital and ran tests for several days. At the end of that, the doc said, "You don't have cancer, but nothing else in your body is working right." I never forgot that sentence of his - what a blessed way to tell me that - no bedside manner for him. During that time, I became allergic to gold. My gold rings were leaving green marks on my fingers.
He sent me to an allergy clinic in Houston. They took my blood, separated the white cells out, and put them on various foods to see what the cells were fighting. That took a few days, then they called me and told me what foods not to eat. Within three days, the constant diarrhea stopped and I began to gain weight. Can food allergy kill you? Yes. The IBS wasn't killing me, but foods were.
I was severely allergic to anything with iodine in it and still am. There is a scar on my arm where I was given an iodine test by putting it just under my skin. It killed my flesh almost down to the bone. It had to heal from the bottom up.
I don't know what killed this man but don't believe it was IBS but allergies could have done it if he didn't have cancer. I was wasting away every week and this man was also losing weight.