Brief Answer:
Better to get a clinical evaluation, examination by a General Surgeon

Detailed Answer:
Hi.
Thanks for your query.
Noted the history about your wife, seen the X-ray of HSG and reports; understood your concerns.
it is not known to have loose motions after HSG although pain and vomiting may occur as there is hydrosalpinx on the left side.
I would advise her the following in such a situation:
Send the stool and blood for lab.
IF there is an evidence of an intestinal infection she may need a course of an antibiotic, metronidazole and probiotics.
Antispasmodic like dicyclomin to relieve the pain in abdomen can be given as required.
Clinical evaluation by a Doctor, preferably a General Surgeon, examination and further investigations if required may be needed is the symptoms do not abate; it is better to rule out any problems as early as possible to get an appropriate management.

I hope this answer helps her, please feel free to ask for further relevant queries if you feel that there is a gap of communication.

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