Overview
Interstitial cystitis is a condition that affects the urinary bladder, characterized by chronic inflammation. It is not secondary to an infection. In many cases, because it remains a diagnosis of exclusion, the condition is often diagnosed late in the patient's journey. Patients often describe pain in the bladder region (suprapubic), with a strong sensation to want to urinate (urgency). This sensation is worsened by filling the bladder and is often relieved by passing urine more often (frequency). This may be during the daytime and/or during the night (nocturia). There may also be other symptoms such as pain or discomfort on passing urine (dysuria) and pain or discomfort during sexual intercourse, known as dyspareunia. Due to these symptoms, there is a profound impact on the emotional, psychological and social well-being of the patient.
Anatomy
The urinary bladder is a hollow viscus located in the pelvis and is anterior to the rectum in both sexes and the uterus in females. It is partially covered in peritoneum on the superior surface. There are four layers.
Mucosa, which contains the transitional epithelium, allows for the stretch of the urinary bladder. When stretched, the surface is smooth, but when relaxed, folds form in the mucosa, known as rugae.
Submucosa, which is composed of elastic connective tissue, further assists with the stretch of the bladder.
Muscularis layer (detrusor muscle) is composed of multiple layers of smooth muscle in multiple directions, which assists with the voiding of the bladder when contraction occurs. They also form a small band that encircles the area between the opening of the bladder and the urethra. This is known as the internal urinary sphincter. The autonomic nervous system controls this layer. Another band around the internal sphincter controls conscious voiding, called the external sphincter, which is composed of skeletal muscle and is innervated by the somatic nervous system.
The fibrous connective tissue layer is the outermost layer of the bladder except for the superior surface, with is covered by the parietal peritoneum.
The bladder is also divided into a triangular area called the trigone. This is formed by the openings to each ureter and the opening to the urethra. This forms three apices. The openings of each ureter are also covered by a small flap of mucosa that acts as a valve to prevent reflux of urine into the kidney. The trigone is located at the base, also known as the fundus of the urinary bladder.[