I wanted to share this because even if it helps just 1 person it will be worth it.
DS first started showing signs of OCD when he was in primary school. Over the years it got worse with him checking and counting which he was able to hide at first but then became impossible by his mid teens. He refused to see the GP or talk to anyone that I sought out that could help. At 18 he had to return from university as was trapped in his room all day carrying out his compulsions. At home it was no better and my husband and I watched helplessly as our lovely boy was in such a state carrying out his compulsions he could barely function. I researched for hours on the internet and in desperation looked into a possible link with the gut. I paid £400 for a stool test and it came back as abundance of a waterborne parasite in his gut. I didn’t tell him as I knew it would freak him out and I put him on a parasite cleanse. By the final week - week 3 he had many violent poos and felt quite ill as the parasites left his guts. Almost like a miracle his OCD has completely disappeared and he has had not 1 compulsions since. This may not be the answer for everyone who has this dreadful illness but like I said at the beginning, if it helps just 1 person it will be worth posting.