However it is counter intuitive that constipation could not be linked to bowel cancer. It is known that most cancers are caused by repeated insults at a cellular level usually by toxins or irritants that the cells come into contact with or or absorbed into the cell. If bowel cancer is caused by such irritants within the bowel than the longer they are in contact the intestine or mucosa than the more likely it is damage to occur which may result in cancer. Conversely the less time that any toxins spend in the bowel, ie when there is a shorter transit time, the less likely the bowel is to be irritated.

As Dr Briffa points out, epidemiological evidence is open to widely varying interpretations because of confounding factors that are extremely difficult to control for. That doesn’t mean that epidemiological evidence is useless but simply has to be interpreted with caution. Unless medical orthodoxy has changed, both African and Asian people settling in a western country tend to have much higher rates of diabetes, hypertension and arterial disease than their counterparts who remained at home. Surely this can only be attributed to a change in lifestyle, most likely involving diet, possibly alcohol intake and tobacco consumption and perhaps reduced exercise. But if I had to pick one of these it would be diet. I wonder if Africans or Asians who emigrate here also increase the risk of bowel cancer? Perhaps somebody could enlighten me.

My bowels open twice a day at least and if I miss one day I don’t feel 100% well. They only open once or twice a week I would be very worried, though the medical orthodoxy has always been that such things really don’t matter. I beg to differ.