What are the symptoms of appendicitis?
Here is the article which I’ve got from the wikipedia.

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Appendicitis is a condition characterized by inflammation of the appendix. All cases require removal of the inflamed appendix, either by laparotomy or laparoscopy. Untreated, mortality is high, mainly because of peritonitis and shock.[1] Reginald Fitz first described acute and chronic appendicitis in 1886,[2] and it has been recognized as one of the most common causes of severe acute abdominal pain worldwide.

Causes

Location of the appendix in the digestive system
On the basis of experimental evidence, acute appendicitis seems to be the end result of a primary obstruction of the appendix lumen.[3][4] Once this obstruction occurs the appendix subsequently becomes filled with mucus and swells, increasing pressures within the lumen and the walls of the appendix, resulting in thrombosis and occlusion of the small vessels, and stasis of lymphatic flow. Rarely, spontaneous recovery can occur at this point. As the former progresses, the appendix becomes ischemic and then necrotic. As bacteria begin to leak out through the dying walls, pus forms within and around the appendix (suppuration). The end result of this cascade is appendiceal rupture causing peritonitis, which may lead to septicemia and eventually death.
Among the causative agents, such as foreign bodies, trauma, intestinal worms, and lymphadenitis, the occurrence of an obstructing fecalith has attracted attention. The prevalence of fecaliths in patients with appendicitis is significantly higher in developed than in developing countries[5], and an appendiceal fecalith is commonly associated with complicated appendicitis[6]. Also, fecal stasis and arrest may play a role, as demonstrated by a significantly lower number of bowel movements per week in patients with acute appendicitis compared with healthy controls[7]. The occurrence of a fecalith in the appendix seems to be attributed to a right sided fecal retention reservoir in the colon and a prolonged transit time[8]. From epidemiological data it has been stated that diverticular disease and adenomatous polyps were unknown and colon cancer exceedingly rare in communities exempt for appendicitis[9][10]. Also, acute appendicitis has been shown to occur antecedent to cancer in the colon and rectum[11]. Several studies offer evidence that a low fiber intake is involved in the pathogenesis of appendicitis[12] [13][14]. This is in accordance with the occurrence of a right sided fecal reservoir and the fact that dietary fiber reduces transit time[15].

Symptoms

Symptoms of acute appendicitis can be classified into two types, typical and atypical.[16] The typical history includes pain starting centrally (periumbilical) before localizing to the right iliac fossa (the lower right side of the abdomen); this is due to the poor localizing (spatial) property of visceral nerves from the mid-gut, followed by the involvement of somatic nerves (parietal peritoneum) as the inflammation progresses. The pain is usually associated with loss of appetite and fever, although the latter isn't a necessary symptom. Nausea or vomiting may occur, and also the feeling of drowsiness and the feeling of general bad health. With the typical type, diagnosis is easier to make, surgery occurs earlier and findings are often less severe.[16]
Atypical symptoms may include pain beginning and staying in the right iliac fossa, diarrhea and a more prolonged, smoldering course. If an inflamed appendix lies in contact with the bladder, there is frequency of urination. With post-ileal appendix, marked retching may occur. Tenesmus or "downward urge" (the feeling that a bowel movement will relieve discomfort) is also experienced in some cases.[17]
Unlike acute appendicitis, chronic appendicitis symptoms can vary from patient to patient. So much so that "There are no typical findings or routine diagnostic modalities to diagnose chronic relapsing appendicitis. It is a diagnosis of exclusion..."[18]

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Although there are some symptoms, but according to my doctor, it could be vary from one person to another. Some people could feel several symptoms while the others could feel only one of them. This was the reason why I didn’t believe the first doctor who told me that it was appendicitis, because I thought that the symptoms of appendicitis is not only the undefined stomachache as I got that night. It should be more than that. But I was wrong. It could be only that.
But after all of this, I think I can conclude one thing, the most trusted symptoms of appendicitis actually is when you push your right-bottom stomach and you feel pain, it should be appendicitis.

Now, we’ll talk about the cause of appendicitis. Most people believe that the cause is because you eat too much food contains of seed. That’s not totally correct. According to my doctor, the cause is 80% of constipation and 20% of seed. So you must be careful of those problems, because I don’t think that I have both of them, while I always try to keep eating vegetables during meal. But, in fact, that was not enough. There was something going wrong in my stomach and unfortunately, I didn’t realize that.

So, just be careful and keep your body healthy.