Where does “rektumprolapsi” come from?

rektumprolapsi (Finnish) comes from German Rektum, from New Latin rectum, from Latin rectum, from Latin rectus, from Latin regere, from Latin rego, from Proto-Italic regō, from Proto-Indo-European h₃réǵeti — to straighten, to right oneself; right; just.

Ancestry of “rektumprolapsi”, step by step

rektumprolapsi traces back through two separate lines of ancestry.

via German Rektum

StepLanguageWordMeaning
1GermanRektumrectum
2New Latinrectumaccusative supine of regō; nominative neuter...
3Latinrectumaccusative supine of regō; nominative neuter...
4Latinrectusruled, having been ruled, governed, having been...
5Latinregeresecond-person singular future passive indicative...
6LatinregoI rule, govern; I guide, steer; I oversee, manage
7Proto-Italicregō
8Proto-Indo-Europeanh₃réǵetito be straightening, to be setting upright
9Proto-Indo-Europeanh₃reǵ-to straighten, to right oneself; right; just

via Finnish prolapsi

StepLanguageWordMeaning
1Finnishprolapsiprolapse
2Latinprolapsuscollapsed
3LatinprolaborI glide, slide, slip forward; I collapse, decay
Every word from Proto-Indo-European h₃reǵ-Every word from Proto-Indo-European h₃réǵetiEvery word from Proto-Italic regō