The cruelty and indignity of the situation is manifest.
- Rohingya Muslims confront hunger and disease in refugee camps
- Kutupalong camp has doubled in size since the influx began and is now home to 100,000 people
- MSF has prepared an isolation unit in the Kutupalong medical facility to contain cholera, measles cases
"There is no toilet here," 40-year-old Bodhi Alam says.
He is a Rohingya refugee who fled Myanmar for Bangladesh two weeks ago, and now lives in a makeshift shelter in the Kutupalong refugee camp.
They have escaped persecution and violence in Myanmar, now surviving Rohingya Muslims confront hunger and disease in this supposed safe haven.
"We have to go into the forest for the toilet," Mr Alam's wife Noor Shafah said.
The couple have six children, two of whom are disabled and cannot walk.
"They are keeping their stomach empty intentionally, not eating much rice, in order to avoid going to the toilet," their mother said, casting a forlorn look at the crippled boy and girl — 15-year-old Jahangir Alam and 12-year-old Hadia Begum.
"People are suffering a lot," their father said.
The Kutupalong camp where they are has doubled in size since the influx began nearly a month ago, and is now home to an extra 100,000 people.
"As there are large numbers of refugees now, we are facing shortage of food, drinking water, toilets and many other things," Mr Alam said.
In several days, reporting from different parts of the newly-settled camps, the ABC has seen only one latrine under construction.
On the banks of streams where children swim and women wash rice to cook, human faeces is everywhere.
The charity Medecins Sans Frontieres (MSF) says the dearth of facilities and immunisation presents a "very high risk" of infectious disease.
"The situation in the camps is so incredibly fragile, especially with regard to shelter, food and water and sanitation," MSF's emergency coordinator Robert Onus said in a statement.
Such is the expectation of worse to come that MSF has prepared an isolation unit in the Kutupalong medical facility in the hope of containing cholera or measles cases.
It has been a month now. Why?
Speak to aid workers on the ground here, and you will hear a line that goes: "I've been to Rwanda, Syria [insert refugee crisis here] but I've not seen anything like this."
In short, the speed and scale of the exodus has exceeded both the prediction and capability of the world's collective humanitarian machinery to respond quickly.
A place to stay, not to live
There is another very simple reason. There are no roads. No-one can get in.
From Cox's Bazar, the closest airport, a narrow two-lane highway leads down through the mushrooming settlements to the border.
That road is now choked by traffic; both human and a combination of official and ad-hoc aid that is impossible to organise.
The chaos has even proven fatal — several refugees have died falling under the wheels of trucks they were chasing in the hope of a handout.
But head off that one road, and things worsen still.
The landscape along the Myanmar-Bangladesh border is defined by steep hills, which sit like islands between rice paddies.
Now, late in the monsoon season, both are muddy and impassable.
It is here that the makeshift settlements spring up — and sometimes disappear — if their inhabitants think they have a better chance of aid elsewhere.
Put simply, it is a nightmare — both for the refugees crammed in here, and the people trying to help them.
Resistance to anything 'permanent'
Then there is the politics.
Bangladesh already hosted an estimated 400,000 Rohingya before this influx began and has openly stated it cannot support, nor does it want, this latest influx to stay.
So, there is a resistance to anything too permanent.
Aid agencies have had difficulty in getting the number of workers they need into the country, even going so far as to publicly call on Bangladesh's Government to speed up approvals.
"Timely processing of permissions and visas for surge staff is required to support scale-up of operations," reads a situation report produced by the International Organisation for Migration's coordinating body this week.
It notes "some NGOs have begun receiving permissions".
Bangladesh has promised more space and shelter, but the Government is concerned if it does too much it will face difficulty convincing the international community to pressure Myanmar to allow the Rohingya safe return.
Right now, no other country is volunteering to accept them either.
It is little wonder the Rohingya are sometimes termed "the world's most unwanted" people.
"God only knows where my home is," Bodhi Alam said, who had fled to Bangladesh previously in 1992 only to be deported again a year later.
"If I come to Bangladesh, they say its not my home, and if I go back to Myanmar, they say same thing."