I'm in Kuala Lumpur right now, and have a ticket to go to Ho Chi Minh.
However, I consider visiting Singapore for a few days and then come back to KL. I consider a bus trip.
But I'm fearful of being denied of the re-entry when I come back from Singapore due to the short interval. That would invalidate my travel to HCMC, and I would have to buy a new ticket from Singapore for another place (except Malaysia).
Is it possible to make a short trip to Singapore from Malaysia and then come back?