Renal colic is a type of abdominal pain commonly caused by kidney stones. Renal colic is a type of abdominal pain commonly caused by kidney stones. Renal colic typically begins in the flank and often radiates to below the ribs or the groin. It typically comes in waves due to ureteric peristalsis, but may be constant. It is often described as one of the most severe pains. Although this condition can be very painful, kidney stones usually cause no permanent physical damage. The experience is said to be traumatizing due to pain, and the experience of passing blood, blood clots, and pieces of the stone. In most cases, people with renal colic are advised to drink an increased amount of water; in other instances, surgery may be needed. Preventive treatment can be instituted to minimize the likelihood of recurrence.