Embarin issue, constipation..?

i have a slight problem, i cant seem to 'go' when im away from home, and im away alot, i was at glasto, a festival, a month or so back and it ruined my time there, as i was so so bloated and felt to fat to were any of my clothes haha, and im going away again to another festival in two days and i was wondering if theres anything i could take to kep me regular, eg some sort of herbal tea. i dont wanna take laxatives as i abused them for a year a few years back and it really messed my sytem up.. any ideas would be appreciated. Oh and ive tried high fibre foods apples dried fruit etc..