Based on what you're describing (pain about 30 minutes after eating, followed by an urge to have a bowel movement, going on for 5 days), here are the most likely explanations, from most to least common:

1. Exaggerated gastrocolic reflex (often triggered by a recent GI infection) Normally, eating triggers a reflex where the stomach signals the colon to contract and move things along, this is why many people feel an urge to defecate after meals. In some people, especially after a stomach bug, this reflex becomes exaggerated and produces cramping pain plus urgency every time they eat (Costanzo Physiology; Ganong's Review of Medical Physiology). This pattern commonly develops after a bout of acute gastroenteritis, even a mild one you may not have clearly noticed, and a 2024 systematic review in Gut found that a meaningful proportion of people develop IBS-like symptoms in the weeks following acute gastroenteritis (PMID: 39013599).

2. Acute gastroenteritis (viral or bacterial), possibly still resolving Abdominal pain with diarrhea, especially if it started acutely, is most often gastroenteritis, from a virus, bacteria, or contaminated food (Tintinalli's Emergency Medicine; Bailey and Love's Short Practice of Surgery). Five days is a fairly typical duration for this to still be settling down, particularly bacterial causes.

3. Food intolerance or sensitivity Lactose intolerance, or intolerance to fatty/spicy/high-FODMAP foods, can cause pain and loose stools within 30-90 minutes of eating. If it's specifically tied to certain foods (dairy, greasy food, etc.) rather than everything you eat, this becomes more likely.

4. Irritable bowel syndrome (IBS), diarrhea-predominant IBS classically causes pain relieved by defecation, and about two-thirds of IBS patients report symptoms worsen after meals (Goldman-Cecil Medicine). Usually IBS is diagnosed only after symptoms persist beyond a few weeks, but a first flare can look exactly like what you're having.

When to see a doctor promptly - please seek medical attention if you have any of these, since they point to something needing more than home management:

I can't give you a definitive diagnosis without an exam and possibly stool testing, but five days of a consistent post-meal pain-then-diarrhea pattern is worth having checked if it doesn't resolve in the next couple of days.

I can't prescribe medication - that requires an in-person or licensed clinical evaluation, since the right treatment depends on the actual cause (infection vs. intolerance vs. IBS vs. something else), and I don't have exam findings, stool tests, or your full history to know which one this is.

What I can tell you is what's generally used for each likely cause, so you know what to expect or discuss with a doctor or pharmacist:

Since your symptoms have lasted 5 days, my honest recommendation is to see a doctor (in person or via telehealth) in the next day or two. They can examine your abdomen, ask about red-flag symptoms, and likely order a basic stool test if needed, that result determines whether a prescription is appropriate and which one. Taking antibiotics or antidiarrheals without knowing the cause can actually make some conditions worse.

If you want, I can help you prepare a clear symptom summary (timing, triggers, associated symptoms) to bring to that appointment so you get a faster, more accurate diagnosis.