As per 245CD(j), you should be fine after provinding the medical certificate:
245CD-SD Specified documents
The specified documents referred to in paragraph 245CD(j) are:
A personal letter from the applicant which includes full details of the reason for the absences and all original supporting documents in relation to those reasons - e.g. medical certificates, birth/death certificates, information about the reasons which led to the absence from the UK.
It is better if you can attached an ILR list of absences spreadsheet template from here (
http://www.immigrationboards.com/viewtopic.php?t=64235) along with the medical certificate.
Check the details here:
http://www.ukba.homeoffice.gov.uk/polic ... es/part6a/