You are wise to be concerned about rectal lymphogranumoma venereum (LGV), but it is very unlikely you have it.

As you probably know, but for other users who may read this:  LGV is caused by particular strains of chlamydia which are more virulent and can cause more severe symptoms than most types of chlamydia. For 15 years there has been a significant rise in frequency of rectal LGV among men haven sex with men. When LGV is confirmed or suspected because of severe symptoms, treatment with doxycycline for 3 weeks is recommended, instead of the usual 1 week given for uncomplicated chlamydia. However, not all rectal LGV symptoms are severe; even when caused by LGV types of chlamydia, mild or asymptomatic infections are cured by doxycycline for 7 days. (This is something I know about. As it happens, five years ago I wrote an editorial that pointed out that 7 days treatment works just fine for the large majority of rectal LGV if symptoms are not severe:  https://pubmed.ncbi.nlm.nih.gov/29642122/ )

Sometimes rectal LGV extends above the rectum, i.e. higher into the colon, and you are right to be concerned symptoms can be virtually identical to those of colonic diverticulitis. However, if you were not having prominent rectal pain, bleeding, and perhaps low abdominal pain when your chlamydial infection was diagnosed, it is very unlikely it was due to LGV and almost certainly 7 days of doxycycline was sufficient for reliable cure. To your specific questions:

1) Most clinics or STD providers do not routinely test rectal chlamydia for LGV, but some may do so. I imagine it might be routine at some of your country's sexual health centres. (Collectively, Australia's federally supported SHCs are, in my opinion, the world's very best network of STI/HIV clinics.)

2) There is no evidence that the LGV strains of chlamydia are any more transmissible or contagious than others. Auto-inoculation (self transfer to new body sites) is never known to occur with chlamydia.

3) As implied above, even if you happened to have an LGV strain of chlamydia, you probably were cured with the standard 7 day course of doxycycline. However, if your diverticulitis symptoms are active -- low abdominal cramping, perhaps blood in stools, etc -- it would be reasonable to have another rectal swab for chlamydia testing and, if positive, testing of it for LGV.

As implied above, guaranteed expertise is available at your nearest SHC. (If you're near Melbourne or Sydney, those SHCs are the best of the best -- but all are excellent.)

I hope these comments are helpful. Let me know if anything isn't clear.

HHH, MD

It sounds like your doctor is quite knowledgeable about these issues. Loose stools is not a symptom that raises suspicion of chlamydia or LGV.

Thanks for the thanks and the holiday greetings. Merry Christmas to you as well.

Sorry in advance, unfortunately like many i have fallen victim to the anxiety linked to STIs.. 

A final question if you are able? I woke this morning with a clear thin sticky discharge from my penis it was a single episode I don't recall becoming aroused during my sleep and was not so when i woke. I know I've been tested twice now for gonorrhea and chlamydia via urine both negative but as is the nature of myself my anxiety is getting the better of me?

That completes the two follow-up exchanges included with each question and so ends this thread. I hope the discussion has been helpful. Best wishes and stay safe.