Hi eleonora
does she have other symptoms e.g abdominal pain,dull or sharp pain,radiation of pain,any fever,headache, diarrhea,blood with vomiting,about lmp last mesntrual period,medicati on?
what are findings on ph/exam?
lab data?
D/DX rule out of pregnancy before any prescription.

other symptoms e.g icter,bilious vomiting,change of bowel habit,hematoche zia,chest pain,cough,weig ht loss,anorexia
in past/hx is there any hx of GERD,gastric ulcer,erosive gasritis.liver disease,hepatit is,hiatal hernia or umblical hernia,hx of abdominal surgery for rule out adhesive band and obstruction?

anorexia nervosa

does the meals give her relive ???
what did she ate and does she drink alcohol ???
when does the pain occure .... morning ,evening,after or before meals ???
does she feel relief after vomiting??
what are the doses of diclofenac ,how many times a day,for how long ??
any head trauma ,migraine,concu ssion???
blood morfology + CRP ,panceratic enzymes ,AST,ALT,ALP USG,gastroscopy ,
gastric ulceration , duodeanal ulceration ,gastric erosion wich can be coused by diclofenac...
gastritis ,pancreatitis ,cholecystitis ,food posining, pregnancy and a lot more

There is no correlation between vomiting and meals. Neither meals nor vomiting alleviate the abdominal discomfort which is rather constant but not very intense.
She admits drinking a glass of wine every night but has never smoked.
There is no history of head trauma.
The pregnancy test is negative.
FBC, CRP, amylase, AST, ALT, ALP negative.
Abdominal ultrasound normal.

Hi eleonora
What are the findings in endoscopy?

Hello! I thought that it would be nice to sum up. So here we go!
Our patient is a 24yo old female with a 7 wk history of nausea, vomiting, a dull pain in the upper epigastrium, loss of appetite and constipation (harder and less frequent stool). No other mentioned symptoms. Past medical history clear. No relief with Gaviscon and ranitidine. She's on the Pill, takes cyclizine and occasionally diclofenac after a knee injury few months ago.
Since she's at a reproductive age and on contraception the 1st thought would be pregnancy. The pregnancy test was however negative.
The symptoms seem to be related with the GI tract so we can start by ruling out gastrointestina l causes.
From this point of view, the second most probable diagnosis would be a NSAID-related gastritis since she's been on diclofenac for some time now. In this case a gastroscopy would be helpful.
Apart from these diagnoses and as you've already mentioned above, there is a number of diagnoses concerning the GI tract that should also be excluded. Here's a list from mouth to anus including the previous answers (with a couple personal additions) :

1) GERD
2) peptic ulcer
3) cholecystitis
4) pancreatitis
5) gastroenteritis
6) bowel obstruction
7) appendicitis
8) inflammatory bowel disease
9) irritable bowel syndrome

At this point my question is what information from the patient's history could one use to support or exclude these diseases and what tests should be ordered in each case.

With the above I simply intend to put into order everything that has already been mentioned to make it seem less chaotic.

No, she has never smoked? Why did u ask?

You should rule/out anorexia nervosa.and then put negative mark for me:)