Ds1 has been complaining ove rthe past few days of having 'a sore bottom' (not itchy). Since he went to bed over a hour ago he's been screaming with pain, saying it's his bottom... I've looked but can't see anything - no redness or bleeding. I've given him calpol & neurofen to no avail. Can't get thru to NHS Direct... should I take him to casualty/ What can it be????