Many things can go wrong when a child enters changeover, ranging from under-developed tentacles, to running out of Selyn before breakout, and varied other physical and psychological problems.
(Source: Index card file. Sime Surgeon - http://www.simegen.com/sgfandom/rimonslibrary/surgeon/SURGEON1.html) Common syndrome among children raised out-Territory --- soaked up common fear of simes; when confronted with becoming sime, the subconscious overwhelmed the intellect and tried to fight off changeover. Uses up selyn supply prematurely --- feels Need, which triggers breakout contractions while tentacles and nerve system are not yet ready --- which can only increase sensation of Need and waste selyn. Can die of Attrition before breakout.
Prineridine gel slows this process down.
(Source: Index card file. Noreen's syndrome --- Unto Zeor, Forever) A changeover pathology, rather rare, but Lankh's machine seems to induce it. (Didi Rill)
Renal shutdown, arrested stage five followed by a sudden onset of breakout, breakout contractions often premature, not enough fluid buildup to rupture (die of attrition.)
Nerve sheath lesions, membranes on openings too thick anyway.