We used Levo about 3 months ago to try to get rid of Maltophilia. It didn't get rid of the bacteria, but it didn't make my daughter feel bad. She didn't complain at all of stomach issues or headaches...she acted as if she weren't on it. She went to school and did fine during the entire course.
Our doc did advise me to put a Culturelle capsule (opened) into the feeding bag or to just make sure she swallowed one each day. This kept her bowel well populated with the good bacteria so she didn't get the runs.
Good Luck,
Michelle, mom to Tori w/CF and a G-tube, 5 yrs. old