Lisa -
This has been bugging me for the last few days since I read your post.  "Sad,
droopy  baby" just kept going around my head and this morning it finally
clicked.  This baby should be checked for infant botulism.  It produces
"descending, flaccid paralysis".  From R. Lawrence p 437 "When a previous
healthy infant under 6 mos of age develops constipation, then weakness, and
difficulty sucking, swallowing, crying, or breathing, botulism is a likely
diagnosis.... Clinically, constipation, weakness, and hypotonicity in a
previously healthy child botulism until ruled out, especially if there have
been recent dietary changes."  BF infants have later onset and milder symptoms
than AF infants.  Honey can cause botulism, but only in 35% of the cases.
Hope this helps.
Cynthia D. Payne
LLL of Berkshire County Massachusetts