It is not like castration, it involves mutilating the genitalia such that the victim can never derive any pleasure from sex. FGM is more like cutting off the glans penis (the bellend). Also since the female genitalia is a not a protrusion that can be cut off easily and it to be functional for insertion after mutilation, the process can horrifying and drawn out. From the wiki:

Comfort Momoh, a specialist midwife, describes Type III: "[E]lderly women, relatives and friends secure the girl in the lithotomy position. A deep incision is made rapidly on either side from the root of the clitoris to the fourchette, and a single cut of the razor excises the clitoris and both the labia majora and labia minora." Girls "may be pinned down so firmly that bones may fracture".[47] In Somalia the clitoral glans is removed and shown to the senior female relatives, who decide whether enough has been amputated. After this the labia are removed.[48] The amputated parts might be placed in a pouch for the girl to wear.[49]

A single hole of 2–3 mm is left for the passage of urine and menstrual fluid by inserting something, such as a twig, into the wound.[i][50] The vulva is then closed with surgical thread, agave or acacia thorns, or covered with a poultice such as raw egg, herbs and sugar.[28]:491[51] To help the tissue bond, the girl's legs are tied together, often from hip to ankle; the bindings are usually loosened after a week and removed after two to six weeks.[52][28]:491 The result is a "drum of skin extending across the [vaginal] orifice except for a small hole", Momoh writes.[47]

If the remaining hole is too large in the view of the girl's family, the procedure is repeated. The vagina is opened for sexual intercourse, for the first time either by a midwife with a knife or by the woman's husband with his penis.

I'm guessing (hoping) that Bohra style FGM is not so extreme and "only" involves removing part of the clitoris.