Concerned about WBC after hospital visit

Asking on behalf of best friend (25F) who just went to the hospital with vomiting and diarrhea; she thought she was having some problems with her gallbladder in the past so we thought it might be an infection related to that. They took her blood and most things were normal (platelets, RBC, hemoglobin, etc).

The only things that were high were the WBC count (16.4), specifically her neutrophils (14.1). Her other WBC’s were within normal ranges. Her MPV was also slightly high, which it was a few years ago too (it’s lower now) and her doc believed it was related to her not getting enough vitamin D. She had no fever, but did have chills and mild tachycardia (which has gone away) and was very anxious.

They gave her a full abdominal and pelvic CT with contrast to check for stones, infections, or other issues and found nothing, and discharged her without repeating her CBC and saying they thought her WBC was elevated because of vomiting and dehydration due to a “stomach bug.” They gave her fluids, toradol, zofran, and discharged her.

It’s been 5 days since the ER trip and overall she’s feeling a lot better but she has bad OCD and is persistently worried about her elevated WBC. Could it really be that high just from vomiting and from a stomach bug? Should she worry about blood cancers or anything else? She’s going to follow up with her primary care physician within the month but could use some reassurance in the meantime.

EDIT: She did just have an ingrown toenail removed about 2 weeks ago and was on an antibiotic for an infection in the toe in relation to it that she just finished yesterday. They didn’t give her a new antibiotic because of being on this one.