This can happen due to prostate enlargement. The symptoms of prostate enlargement are fluctuating and there may be some poor stream, increased frequency, urgency etc, earlier too before the retention; but may have been thought of as interstitial cystitis.
You may consider following investigations;
1) Urine culture; a prostatitis can also cause retention and that would be ruled out by it.
2) Ultrasound of prostate; for assessing enlargement.
3) Video urodynamics; this indicates about the bladder contraction, its nerve supply, pelvic floor issues, outflow obstruction etc.
You may ask meanwhile medications for prostate enlargement from your doctor, before removing the Foley.
Please feel free for your follow up questions.
I would be happy to assist you further, if you need any more information.
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