constipated 5 1/2 month old

When my kids were babies, they were all very regular - messy diapers at least once a day. You said he's being finicky about food - is he eating fruits yet? They generally will help get things moving, especially prunes or apples.
Yucky nose and finicky - is he teething? Sometimes mine would get a runny nose with teeth, but it was clear not yellow or green mucus.
If the runny nose is yellow or green, that generally indicates infection of some sort and if it continues, I would take him to the dr.

runny nose, loss of appetite, constipation are all signs of teething. Unfortunately they're also signs of the common cold and other illnesses. To help relieve constipation, try feeding him apple juice (watered down at least half and half), or baby's first foods Pureed prunes, these you can mix in with rice cereal or even formula. For teething, try a cold wet washcloth. buy several, so you can grab a clean one if it falls on the floor or something. For runny nose, use an aspirator bulb (they usually send you home from the hospital with one) and bring him into the bathroom with you and run a shower so the room steams up. That should help with congestion. GL!

with the washcloth, just let him hold it, so he can suck on it, chew it, whatever.. or rub his gums gently with it. I used baby oragel toothpaste with a baby tooth brush too. They recommend those for 6 mos and up though. GL!

but should i be bringing him to the doc since it's been a few days since his last bm?

Is he breastfed? If so, no poop for days is NORMAL.

Constipation is whe they strain to pass hard dry poops. If THAT is happening, see the doc.

If formula fed, and if cereal is in the picture...back off the cereal and up the liquids.

Oh. And please, no Karo. It's a botulism risk.

well he is formula fed. he hates cereal but before this he was finishing a jar a day (3 feedings) of natures goodness baby food. he had bananas one day and applesauce the next (both were stage 1 of course). he had 2 bites of squash (hated it) and half a jar of carrots. maybe that caused it, it was the first times he had jarred baby food really.