You asked

My baby has diarrhea, should I stop breastfeeding?

The answer is no, definitely not.There is no benefit to you or your baby that can be gained from stopping breastfeeding. By continuing to breastfeed you will be giving your baby the best medicine possible to cure their diarrhea. Breastmilk is the only fluid your baby requires when they have diarrhea or vomiting and it is only in very rare cases that an additional oral solution would be prescribed. The use of oral solutions is quite common in formula fed babies as formula is not as hydrating or as easily digested. Diarrhea is diagnosed when a baby has more than 12 to 16 stools per day and they are watery in consistency.
Breastfeeding should be the first choice as long as your child can take anything orally. Breastmilk is very quickly and easily digested so even if your child vomits or has diarrhea after nursing they will still retain some of the valuable nutrients. Also, when your child has diarrhea or vomiting it is a good idea to offer more frequent and shorter feedings. This will limit the amount of milk taken in and also soothe and comfort your sick child. It is very rare that a breastfed child would become dehydrated so as long as your baby is nursing well and not showing any signs of dehydration then there is no need for oral rehydrating solutions.
If your baby is showing signs of dehydration, talk to your doctor. Signs of dehydration include:
  • less than 2 wet diapers in a 24 hour period
  • baby is more irritable than normal
  • lethargy
  • weak cry
  • dry mouth
  • no tears (in an older child)
  • skin that stays wrinkly looking when pinched (skin should spring back into place)
  • eyes that stay sunken
  • cool and clammy to the touch
  • fast breathing
  • fast heartbeat
  • fever.
If you have any concerns you should contact your G.P. but remember that dehydration is extremely rare in a breastfed baby and nursing will provide an immeasurable amount of comfort for your sick baby.

More questions

Mums understand the benefits of breastfeeding and some may be tempted by online sources if they're reluctant to breastfeed themselves or are having problems.
Babies can often be fussy in the evenings and you may find it difficult to nurse or settle them. 
Here are ways to know if your baby is getting enough milk
Breastfeeding and medication: what you need to know
What's the difference between breastmilk and formula?
Breastmilk has plenty of iron to last your baby at least the first six months of his life. 
Nipple shields are used if baby wont take the breast or for sore nipples
As of February 21st 2011 the HSE is recommending that all babies, including babies that are breastfed be given 5 micrograms of vitamin D3 a day. This is because recent studies have shown that mothers and...
Spitting up is very common and most young babies spit up at least once a day. This is because their digestive systems are immature which makes it very easy for their stomach contents to come back up their...