Unfortunately there are many reasons to reject someone for ordination. Some of the reasons seem totally bizarre and quite nuts. I don't know what to make of it all. Hopefully some modern monasteries take a more "enlightened" attitude today. I mean puhleeze, a person with just one finger or toe missing is rejected??
Interestingly, if a senior monk ordains someone knowing the newbie has some problem that would disqualify him, the senior monk only incurs a dukkata (to be confessed), but the new monk still remains a monk - the ordination is valid.
Some of the minor reasons to reject someone for ordination:
5) Those who are physically handicapped, feeble, or deformed.
The following list is from the Canon, with passages from the Commentary in brackets: an applicant with a hand cut off [C: at least from the palm] ... a foot cut off [C: at least from the ball of the foot].. a hand and foot cut off ... an ear cut off ... a nose cut off ... an ear and nose cut off [C: in the case of ears and nose, if the cut-off part can be reconnected, the applicant may go forth] ... a finger or toe cut off [C: so that nothing of the nail appears] ... a thumb or big toe cut off .. a cut tendon ... one who has webbed fingers [C: if the fingers are separated by surgery, or if a sixth finger is removed, the applicant may go forth] ... a bent-over person [C: bent-over forward (a hunchback), bent-over back (a swayback), bent-over to either side; a slight crookedness is to be expected in all candidates, as only a Buddha is perfectly straight] ... a dwarf ... one with a club foot (or elephantiasis) [C: if the foot is operated on so as to become a normal foot, he may go forth] ... one who disgraces the assembly [C: through some deformity; (the list here is very long and includes many seemingly harmless characteristics, such as connected eyebrows, a lack of a beard or moustache, etc. This is one area where the Commentary seems to have gone overboard)] ... one who is blind in one eye ... one who has a crooked limb [C: limb = at least a hand, foot, or finger] ... one who is lame ... one half-paralyzed [C: paralyzed in one hand, one foot, or down one side] ... a cripple [C: one who needs a crutch or stool to move along] ... one feeble from old age ... one who is blind... dumb [C: unable to speak or with such a bad stutter that he cannot pronounce the Three Refuges clearly]... deaf ... blind and dumb ... blind and deaf (§ — not mentioned in BD) ... deaf and dumb ... blind and deaf and dumb.
and here are four diseases that disqualify someone...
Four of these diseases are explained in the commentaries.
Leprosy includes scabies, yaws, and psoriasis as well. Apparently, any other disease that causes ulcerating lesions on the skin would also come under this heading. If the disease occurs in small patches the size of the back of a nail in areas covered when fully robed and is in a condition that won't spread further, the applicant may go forth. If the patches are visible on the face or the backs of hands, then even if they are small and won't spread, he shouldn't go forth. If he has been treated so that the patches disappear completely, he may. The Sub-commentary adds here that the "back of the nail" means the back of the nail of the small finger or toe; if the patches are small and in a covered area but still spreading, the applicant should not go forth.
Boils, according to the Commentary, also covers skin excrescencies looking like fingers or cow nipples. If the boils are not spreading, no larger than jujube pits (the same size as olive pits), and in an area covered when fully robed, the applicant may go forth; if they are in an uncovered area, he shouldn't. Acne and warts don't count as boils under this rule.
Eczema covers a wide variety of skin diseases, differing from those included under "leprosy" in that they are not debilitating and do not ulcerate or ooze. Thus ringworm and athlete's foot would come under this category. As under the preceding category, small, non-spreading infestations in an area covered when fully robed would be allowable.
Epilepsy includes both grand and petit mal, as well as cases of seizures caused by hostile spirit possession (!).
(b) A person with goiter. This was apparently incurable at the time. At present, if such a person is cured, he may go forth.
(c) A person afflicted with an "evil" disease. This, the Commentary says, includes such things as hemorrhoids, fistulas, upsets of bile or phlegm, cough, asthma, or any disease that is "chronically afflicting (reading niccātura with the Thai edition of the Commentary), exceedingly painful, disgusting, and disagreeable." AIDS and cancer would come under here.
You can read the whole thing here http://www.accesstoinsight.org/lib/auth ... .ch14.html
It is Thanissaro Bhikkhu's "Buddhist Monastic Code II", Chapter 14... Ordination