When radiation is delivered to the pelvis, the bladder lining sitting close to the uterus is irritated along with the treated area. This can cause a stinging or burning feeling before, during, or after passing urine, a need to go often (frequency), a sudden urge that is hard to hold, and a heavy, bearing-down sensation in the lower abdomen or perineum. This pattern is commonly called acute radiation cystitis.
These symptoms often build during treatment and stand out most near the end and in the first days to weeks after radiation finishes. The irritated lining needs time to heal, so relief usually does not arrive the day after the last session. For many people symptoms ease gradually over several weeks, though this varies and can last longer in some. Still feeling discomfort one week after finishing is not unusual.
It is important to distinguish this from a true bacterial bladder infection (urinary tract infection). The two feel almost identical and are hard to separate on your own. Fever, cloudy or strong-smelling urine, flank pain, or blood-tinged urine may point to infection, which can require a urine test and antibiotics — report these promptly rather than waiting.
Day to day, sipping water often to dilute the urine, and cutting back on bladder irritants such as caffeine, alcohol, spicy food, and carbonated drinks, can help. Try not to hold urine for long stretches. A strong bearing-down feeling may also involve the pelvic floor, so mention it at your visit.
Seek care quickly if pain becomes severe enough to stop you in your tracks, if you see blood in the urine, if fever appears, or if you can barely pass urine. If symptoms do not improve over time or worsen, ask to have the degree of treatment effect assessed.
This article is general information and does not replace medical care. Please discuss decisions about your own symptoms and recovery with your treating team.