@taiwo,
If you are in the United States the common practice is for billing of hospital staff, equipment, lab tests, x-rays, medications and products used while monitoring and treating the illness.
The attending doctor's bill is separate from that. Usually, doctors are not employees of the hospital, they are independent contractors and bill by the hour for their expertise and time devoted to your case. If more than one doctor was called in to attend the patient, expect more than one bill.
I was hospitalized for 12 days a couple years ago and got separate bills from the hospital administration, four attending surgeons, regular doctors, and a bunch of labs. In total, I was being billed from 16 diffferent sources for various aspects of my hospital stay, treatment, and surgery.
In the U.S., most of the time we don't see all of the bills because they get sent to our insurance providers for payment. If you're not insured, you get the joy of auditing, paying and doing battle with all the billers.
I'm not intimately familiar with the billing arrangements in other countries, so if you are not in the US, ignore the above.