This is what the UK
Foreign & Commonwealth Office say about travel to Sri
Lanka: Information for families affected by the tsunami can
be found at
Sri Lanka: Information for Families.

We advise against all but essential travel to the north or
east (other than Trincomalee, Nilaveli and Arugam Bay, but
travellers should be aware that most hotels in these areas
are closed because of damage from the tsunami). Much of the
north and east of Sri Lanka remains heavily mined,
particularly around the A9 road to Jaffna.

The recent tsunami resulted in extensive damage and large
numbers of casualties on the south-western, southern and
eastern coasts of Sri Lanka. A number of hotels and resorts
on the southern and south-western coasts have now reopened.
Anyone planning to travel to these areas should check with
their tour operators and/or hotel before departing to ensure
their hotel is operating normally. Most hotels in the eastern
towns of Trincomalee, Nilaveli and Arugam Bay have yet to
reopen. (For further details please refer to the Natural
Disasters section of this Travel Advice).

There is a threat from domestic terrorism in Sri Lanka.