Do they go to therapy for eating disorders?
Yes, some do but probably fewer people than who actually need to due to a lot of reasons. This includes things like stigma or shame (not just personal shame related to the ED, but also from their communities e.g. certain ethnicities. A lot of this is based on misconceptions or stereotypes, or a lack of awareness. Some also might believe (falsely) any ED or mental health condition, like psychosis, are linked to demonic possession. It’s sound foolish, but some believe it.
A strong element around ED are issues in self control and discipline where essentially it’s taken to an extreme and overdone and usually in response to some form of trauma.
Fasting during Ramadan, and Ramadan itself will not stop anyone from having an ED and shouldn’t be seen as such. The aim of Ramadan is to improve yourself spiritually and mentally, by learning the struggle of those less fortunate than yourselves and to an extent regaining self control and disciple over yourself, spiritually, mentally and physically.
People shouldn’t be eating to excess during iftar at Ramadan time, or at any time really. I think there a Hadith around this too but obvs there are people that do.
You can see how the two might get mixed up wrongly.
Seeking professional help is a must where you need it, even Islamically (despite what a very very small minority might believe) and so you should not be put off.
If you have or think you have an ED, then please seek help as soon as possible. Talk about this with family and friends who you trust and love and will support you, as well as professional help from your GP or there are a number of charities that offer practical advice and support, such as BEAT.
Recognise the signs, and identify the causes or the habits that you feel are impacting your life negatively and try to change these. Try and ignore any negative thoughts, especially if anyone tries to shame you or your family, understand this is based on ignorance and try to have patience and educate people.