Breastfeeding is beneficial to the newborn as breast milk contains nutrients, immune proteins, and other beneficial factors. Some studies suggest that breastfeeding may have a protective effect against developing IBD. It is thought that breastfeeding may help the newborn develop a healthy gut microbiome and immune system by helping newborns develop tolerance to certain bacteria, and thus prevent exaggerated immune responses to bacteria encountered later in life.
| Class of medication | Examples | Notes for breastfeeding |
| Mealamine (5-aminosalicylates) | Asacol©, Pentasa©, Salofalk©, Mesavant©, | Medications are excreted into the breast milk in very small amounts. Risk of toxicity to the child is very small. |
| Sulfasalazine | Sulfasalazine (Salazopyrin©) | Medications are excreted into the breast milk in very small amounts. Risk of toxicity to the child is very small. |
| Corticosteroids | Prednisone (Deltasone©), Budesonide (Entocort©, Coritment©) | Steroids transfer into the breast milk in small amounts, with highest levels in the first 4 hours after taking the medication. |
| Immunosuppressant | Azathioprine (Imuran ©), 6-mercaptopurine (6-MP, Purinethol ©) | These can be continued while breastfeeding. To minimize the drug levels in the breast milk, mothers can pump and dump the first 4 hours of breast milk after taking the medication |
| Methotrexate | Methotrexate (Rheumatrex©) | Contraindicated while breastfeeding. |
| Biologics | Infliximab, Adalimumab, Golimumab | These can be continued while breastfeeding. Although they cross into the breast milk, the levels are nil to minimal. |
| Small Molecules (JAK inhibitors) | Tofacitinib (Xeljanz©) | Contraindicated while breastfeeding. |
| Small Molecules (S1P modulators) | Ozanimod (Zeposia©) | Contraindicated while breastfeeding. |