What causes the pain for people suffering from a colles fracture?

Primarily swelling. Primarily swelling cause the initial pain after a colles fracture. Secondary reasons such as tethered tendons or stretched nerves due to the deformity can also lead to pain. Also compromised blood supply can lead to pain, and in the presence of rapid swelling, numbness, pain on passive stretch of the fingers may indicate an impending emergency needing immediate medical attention.
Trauma to the nerves. The process start when patient fall and continue by damaging the skin and the tendon and the nerves and the bone. These injuries cause swelling, the bone bleed from inside to cause pressure on the nerves, which cause the pain. When the swelling go away the pain cause away.

Related Questions

What could cause broken wrist (colles fracture)?

A fall. The most common cause of a broken wrist is a fall onto your outstretched hand.
FOOSH. Stands for fall on outstretched hand. Thus is still the most common mechanism of injury. By the way while colles fracture is a common moniker for a wrist fracture and colles described the anatomical findings of a typical extra articular distal radius, using colles as a diagnosis lumps too many different well known fractures into one overly broad category, so medical persons should try to specifi.
Fall. The most common mechanism of injury for a colles fracture is fall onto an outstretched wrist. These fractures sometimes require operative treatment.