It probably depends on the person...could be imbalanced hormones, lack of magnesium, toxin overload, shallow breathing. It was odd but when I used to have constipation I would get really anxious. It also has to do with not wanting to accept the present moment. Which is understandable when you have health issues. In the brain the amygdala gets stuck in flight or fight mode. Likely due to the thought processes involved. The simple solutions are deep-breathing & some chammomile tea like celestial seasonings tension tamer. There are so many things that could be causing it...hypoglycemia can be a major factor.