Anyone had a phosphate enema? (Am getting myself checked out so that I can fully commit to TMS work)

Hi,

I'm being investigated for pelvic floor pain and anorectal pain and my colorectal consultant wants me to have a flexi-sigmoidoscopy with phosphate enema beforehand. (I'm reticent to have the flexi-sigmoidoscopy done, but I'm mindful of following the general advice to get myself checked out and cleared for anything sinister like cancer so that I can then mentally fully commit to TMS work.)

If you've ever had a phosphate enema, I'd be grateful to know how you got on with it. Did you have any bad side effects afterwards? - If so, were they long lasting? I've read that some of the possible side effects are electrolyte imbalance, vomiting and anal blistering, so I'm rather daunted at the prospect. (I'm not having the 'full bowel preparation' for the procedure because I'm allergic to senna.)

Thanks in advance for any replies regarding your experiences of this.