Any policy you get should cover medical expenses and an emergency flight home. Always check the fine print. Some policies exclude coverage of ‘dangerous activities’, which can include motorcycling and trekking.
For theft and loss you will require documentation from the Bangladeshi police; getting it can be a hassle and often requires a ‘fee’.
Worldwide travel insurance is available at www.lonelyplanet.com/bookings. You can buy, extend and claim online any time – even if you’re already on the road.