Hi Jeco , i would say its not the Antibiotics giving you constipation at all , Antibiotics if anything make you loose , How is you Diet ,
You may like to try a mild Laxative that will help you ,
Hope all goes well , Take care ,
Jeco, a person's body may react to antibiotics in a number of ways including diarrhea. You may want to consider upping your intake of fluids and possibly trying some probiotics to see if they'll give you a hand. Antibiotics can skew the number and type of beneficial bacteria in your GI tract and probiotics may help to restore that balance. There are a number of good brands on the market including Culturelle, PB8, Align and others. They're worth a try.
Before trying a stimulant laxative, you might consider using either a slightly increased dose of magnesium, or perhaps something like Miralax to give you a hand with the discomfort. There's also the old 'standby' prune juice if you'd prefer something a bit more 'natural.'
Ditto on taking probiotics. You should always take them when taking an antibiotic. Antibiotics are known to constipate because, like CalGal said, they fight all bacteria, the good and the bad. If Align or one of the ones she mentioned doesn't help, try using a stronger one, like Ultra Flora or one of the ones with 10 billion live cultures, as apposed to ones like Align that only have 2 billion. Another thing to do is up your fiber intake and drink a ton of water (60oz a day). This should help move your bowels. Laxatives are a last stitch effort.