「Fluid flow while howling with stiff repeatedly bobbing head」「rubbing scrubbing in buttocks crack with emphasis」「fluid flow from buttocks crack and one's dog」「big flow emphasized from buttocks crack」「fluid flow mercilessly returning and ruthlessly resuming」「fluids with disgorging」all suggest many sorts of reasons to CRY, WEEP TEARS after discovering intestinal-anal parasites, being anally raped, a case of anal and/or penile gonorrhea, fecal release with severe constipation, and so on…particularly「fluid flow with something really big (emphasized) in buttocks crack」will always cause TEARS, and perhaps hollering a bit.
「Flow that returns, resumes」or「fluid flow from canine genitals」(i.e., a 'dick-dog') is that of gonorrheal gleet. A dose of clap was surely one good reason to WEEP, CRY, SHED TEARS in the old days prior to effective antibiotics (and, that window of salvation may be closing again…).
In addition to gonorrhea, a「flow that returns」might be a reference to TEARS that return again and again during the saga of each human's life drama, the way life is. Or, TEARS are a「flow of fluid that causes return.」…perhaps…of someone who has started to depart, walk away, stomp off during an argument.
Some have suggested tearing up and crying when one's lost「dog returns to one's door.」
「Fluid with vomiting.」Certainly, nearly all folks shed TEARS as they retch vomiting, and vomit itself is not exactly liquid in many cases (「filter chunks from fluid」), so this glyph is likely referring to TEARS.
「Flowing」with「buttocks crack」with「big, as wide as two hands」and emphasized might just as well be depicting someone with both hands placed on and spreading the buttocks cheeks as he or she finally relieves a bad case of constipation, getting the flow going again by returning to a previous condition of better health that might bring both TEARS of pain and then TEARS of joy. Use any mnemonic you like perhaps other than「flowing fluids with buttocks crack of your dog」(although no doubt that, too, has been attempted, with someone ending up in tears and badly bitten after attempting to serve into that rectum).

External source definitions …excluding politically incorrect concepts and other meanings deemed offensive today; may include extended definitions, euphemisms, and mnemonics)
Chinese: tears
Japanese EDRDG: tears, weep, cry
Unihan extended: tears; weep, cry