Those symptoms also sound a lot like what I had before having a chunk of my bowl removed due to Chron's Disease.
Might be worth having a look at
NACC the national association for Chron's and Colitis.
From their website
The main symptoms are pain in the abdomen, urgent diarrhoea, general tiredness and loss of weight. Crohn’s is sometimes associated with other inflammatory conditions affecting the joints, skin and eyes
Just to add why not join my campaign for thinner endoscopes! I was walking like John Wayne for a week after a check up
