Bladder Diverticulum
A bladder diverticulum is a pouch or outpouching that protrudes from the bladder wall. It forms when a weak spot in the bladder lining bulges outward, creating an extra pocket where urine can collect. Diverticula may be congenital (present at birth) or acquired due to long-term bladder outlet obstruction, such as from benign prostatic hyperplasia (BPH). Some cause no symptoms, while others may lead to infections, urinary retention, or discomfort.
What is it?
A bladder diverticulum forms when pressure inside the bladder forces the inner lining out through a weak area of the muscular wall. Congenital diverticula are often solitary and due to developmental differences in the bladder wall. Acquired diverticula are more common and usually develop from chronic obstruction, such as from an enlarged prostate or urethral stricture.
Imaging helps identify the diverticulum, determine its size, and evaluate for complications such as stones, infection, or urine retention. CT or MRI may also detect underlying causes like bladder outlet obstruction or associated changes in the bladder wall. Cystoscopy allows direct visualization and may be used when symptoms persist or surgery is considered.
Important to Know
Small diverticula that cause no symptoms may simply be monitored. Larger diverticula or those associated with incomplete emptying can increase the risk of urinary tract infections, bladder stones, or, rarely, tumors arising within the pouch. Treating the underlying cause—such as prostate enlargement—often prevents the diverticulum from worsening.
Red flag symptoms include fever, painful urination, blood in the urine, new difficulty emptying the bladder, or persistent pelvic pain. These signs may indicate infection, obstruction, or complications requiring medical attention. Follow-up imaging may be recommended to monitor the diverticulum or evaluate response to treatment.