Once you’ve made needed dietary changes, you’ll see less bleeding usually within 72 to 96 hours, although sometimes, depending on the degree of irritation to the colon, bleeding will continue until the intestine heals. You’ll know when your infant is feeling better — his or her irritability will lessen, resistance to feeding will go away, and your baby will gain weight.
Dr. Rubinstein says that more than 95 percent of allergic colitis cases disappear by the time an infant is a year old. If that doesn’t happen, you should continue to consult your doctor and perhaps a specialist, and repeatedly introduce milk every three months until your child begins to tolerate it.
“When you change everything and symptoms don’t go away and blood is still in the stool, further evaluation is needed,” says Rubinstein. Your doctor might suggest a test called a flexible sigmoidoscopy to check the intestines for infection, polyps, or abnormal blood vessels close to the surface that could be causing bleeding. It’s also possible, though not usual, that a baby has a rectal fissure or tear.
It’s still important, though, during this time, to introduce new foods into your child’s diet. Babies need to begin to get used to them, and cereals, for example, contain new vitamins and minerals not found in breast milk or formula.