Hi.
Thanks for your query.
Noted the history and understood the concerns.
Pain in abdomen, strange noises, vomiting on eating with bad pains, feeling to go for passing motion but nothing comes out - also called tenesmus, noticed in the morning the dark brown specks in vomitus; all going for a couple of weeks...
This looks to be due to
Gastroenteritis.
Gastritis part causing vomiting on eating and the enteritis part causing pain on eating, colitis part causing the feeling to go, pain but not passing stool due to severe inflammation of the colon and rectum.
I would advise you the following in such a situation:
Get the stool and blood tested.
Ultrasonography of the abdomen.
Get started on a PPI like Omeprazole,
Domperidone for gastritis and vomiting and antacids.
Antibiotic active against intestinal infection.
Antispasmodic for the pain.
Intravenous fluids, electrolytes and antibiotics if vomiting does not stop or have signs of
dehydration and
electrolyte imbalance.