I agree with Teak. He should talk to his GP ASAP.
Have your husband see a doctor.
Nonaxadyl 9 (spelling) which is the sperm killer cream/lotion/liquid can cause that type of reaction for some. If he has never been exposed to this, and this is his first time.... that may be it.
Or if he used a condom that was too small this can also cause that type of symptom (but I have never had that issue for 5 days)
Sometimes after a good round of oral play guys can have an episode of UTI do to bacteria within the females saliva. No the bacteria does not necessarily have to be gonera (SP) or chlamydia to cause a UTI.
Sadly if it is gonerea or chlamydia, that means he has been exposed to it through other sources. Now the good news is, those to diseases can or should be able to be cured through antibiotics. 1 gram of Zithromax (arithromyacin) (4 capsules taken all at once/one single dose) should clear/cure the desease. Doxycycline which is tetracycline should also clear up the problem.... 1 pill every 12 hours for seven days.
Truly there are all kinds of reasons for his condition, some sexual, some not.