Sometimes it takes several flushes to remove even a small amount of waste. Other times water spurts out of the toilet bowl when we flush. This is a brand new toilet and we are quite disappointed. Arnold

Water is not draining completely from the toilet line to the sewage tank. If there is a 'low/little slope' section anywhere in that drain line, solids WILL settle and collect there and cause water to back-up in the toilet drain line. Then the toilet will not flush completely or at all until the 'soft blockage' is cleared out and the drain line emptied. Al 'gravity drain' toilets require a free draining/empty drain line that allows flush water to drain unrestricted. A basement toilet has a pump that 'forces' flush water up and out with enough pressure to sometimes force out the 'soft clog.'

Welcome to our new world of water conservation. If you have a toilet that isn't newer....you have something in your trap weir. Or your flapper is malfunctioning. Or your float valve isn't filling your tank correctly. Or your bowl scouring ports could be clogged. There are sooo many things that could cause this....
.New toilets do this because their design to use less water has reached the point of no-longer working to clear the bowl contents. Plain and simple. It has became the norm to flush once for #1's and flush (how ever many it takes to flush all waste) for #2's.
Back to old styles...You can remove the tank top and inspect the water level in the tank(should be about a 1/2" below overflow tube when full), inspect the flapper(flush the toilet and see if your flapper is staying up long enough to allow enough water to enter the bowl to cause a syphon action that ends with a suction sound and complete emptying of the water from the bowl), flush your toilet and look in the bowl to see if the water spraying from your rim is adequately dispensing water to scour the sides of the bowl, and also look at the jet that shoots water from the bottom of the bowl...aimed toward the outlet portion of the very bottom of the interior bowl. This jet is what starts the syphon action that empties your bowl. If you have something stuck in your trap weir....you probably need to call your Plumber to auger the object out or break it down to a size that will pass into the sewer.
The small ports that spray your sides can be cleared with a 3/16" stiff nylon brush...the jet down below can be cleared with a 1" stiff nylon brush. Flapper malfunction is repaired by replacing the flapper. Incorrect water level in the tank can be fixed by adjusting the valve float. but chances are that if it is all of a sudden malfunctioning...it probably needs to be replaced...good luck and always know how to turn your water off before starting work on your plumbing.
Be gentle with the parts inside your toilet tank. Using a calcium remover when clearing bowl inner ports and jets will help tremendously....but be certain to read the container and follow all handling/use instructions you read. Be careful.....Nick

Remove the toilet & have a plumbing company power snake
as much of the entire homes waste drain as possible

Maybe clogged inside the home on most runs & also out to
the street,have them do as much as they can, out to the street

Remove all toilets, so they can do good job & you can check &
clean them from under it

Have them run a camera down ALL drains & to the street

It sounds like there is a buildup of waste at the top of the trap in the toilet. A closet snake should resolve the problem. You do not have to snake more than a couple of feet of the drain if the buildup is at the top of the trap which is always dry. Try the closet snake and a couple of buckets of hot water while flushing the bowl. Rigid makes a good closet snake and is worth the cost. After clearing, make it a habit of holding down the lever until you hear the tank empty when flushing down solids. Especially with the 1.6 gallon tanks.

Check to be sure small tube is flowing inside the ovefow tube. This is the water that flushes the rim holes, and refills the bowl. If you don't have flow clean or replace the float valve.

if the toilet is old or not cleaned proper, the water jets that shoot the water into the bowl might be clogged. If the jets are clogged with moldor hard water build up the toilet will not flush proper. If you can take a 3 gallon bucket of water and pour straight into the bowl and it flushes fine you have a water pressure problem as described above. the problem also might be that your water inlet system is not letting in enough water to fill the tank. If this is the problem you need to replace the water inlet mechanisim, such as a fluid master. If you use a blue water device that hangs on the side of the tank in the back of the toilet you might have a peice of it under the flapper that takes the water to the bowl when being flushed. Check under the flapper if you put cleaners in the tank.

I don't exactly know what you mean so i will cover all the basics. The fill valve sends fills water in 2 locations. 1) the fill valve fills at the low end (from the bottom to the top) of the tank. This is the flush water level. It needs to be stopped by a float switch before the water overflows into the over flow tube.
2) the fill valve fills water via a small tube at the top of it which this tube NEEDS to be pointed into the overflow tube with a high arch. THIS water is filling your toilet bowl section to proper flushing height. If your water in your bowl does not reach proper height and someone removes this tube to aim it into the tank where the other water is stored, THEN you may have the problems you described and you will need to do several flushes to remove waste.
SO to reiterate 1) make sure your float cuts off and stops the filling cycle before the water flows into the over flow tube. This is done from 1 or 2 adjustment screws. and 2) make sure the small black tube is aimed down into the over flow tube with a good arch. The arch prevents back siphon.

If you raise the water level in the tank it will double flush. I suggest you change out the toilet to a Toto or Kohler class five flush action.

Hi
try to increase the amount of water for each flush .

hello, this is a standard toilet you will need to inspect the flapper that is the rubber flap that holds the water up in the tank it works when you pull the lever it pulls the chain upward and lets the water flow if this flapper is old it may not stay up long enough for the water to flow. open the tank top and flush the toilet see if this flapper is staying up long enough and giving the tank enough time to empty if not change this rubber flapper its inexpensive part.
if this is not the reason then you need to adjust your water filler valve there should be a small screw on top of the pivoting float arm
if you have to adjust it for the water limit line inside the tank this will be the proper amount of water needed to flush once completely

also check that the chain lenth on the pull lever is not pulling the flapper down quicker than its supposed to,

try this let me know your results
hope it helps