Dozens of people were admitted to the Sadar Hospital with diarrhoea in the last two days.
Dr Zahid Nazrul Chowdhury said the worst affected areas are Haripur and Dariapur of the municipality.
He said 144 people were hospitalised with the disease. Of them, 72 people are currently undergoing treatment at the hospital while the rest have left after receiving treatment.
The sudden rise in the number of patients led to accommodation crisis at the hospital. Many patients were treated on the corridor.
Doctors have advised to boil water before drinking.