I have often found that:
[li]Constipation is accompanied by severe headache - and when the former is relieved, the latter goes away.[/li]
[li]If I’m in a situation where I have to delay defecation (for example, a long meeting or journey), I will most likely develop a headache.[/li]
[li]If I already have a headache, it feels abruptly better after a routine visit to the toilet for number 2’s.[/li][/ul]
Why is this?