Hi thanks for asking question.
Regarding your gastrointestinal problem below are some possibilities.
1.First you might have chronic
bacterial enterocolitis as pain is it lower abdomen.
Stool examination can be done.complete blood examination also can be done.antibiotic given for it.
2.Second it could be chronic
parasitic infection by hookworm or roundworm like.stool occult blood examination useful.
Albendazole needed for it.
3.If you have alternate diarrhea and
constipation then
irritable bowel syndrome like function bowel disease might be cause.
For constipation regular exercise, more water , fiber useful.
4.If still symptoms increasing ultrasound and colonoscopy could be helpful.which might reveal erythematous area in colon and biopsy can be taken to rule out
microscopic colitis like condition.
Ulcer also can be ruled out by it.
I hope my suggestion will be helpful to you.
Dr.Parth goswami