Brief Answer:
Hemorrhoids very likely.Get yourself examined by a MD.

Detailed Answer:
Hi,
As per the history given by you most likely cause of your problem is Hemorrhoids. Hemorrhoids are swollen veins in the lowest part of your rectum and anus. Sometimes the walls of these blood vessels stretch so thin that the veins bulge and get irritated,
especially when you poop.
According to standard texts Hemorrhoids are classified as-
Grade 1:hemorrhoid bulges into the canal but does not prolapse or fall completely into it. These may bleed.
Grade 2: hemorrhoid protrudes past the anal verge with straining for a bowel movement or passage of flatus, but spontaneously return to their original internal position once the straining has subsided.
Grade 3: the hemorrhoid may protrude past the anal verge without any straining and requires the patient to push them inside manually.
Grade 4: the internal hemorrhoid always stays protruded or prolapsed and is at risk for thrombosis or strangulation should the anal muscles go into spasm.
Three types of managements are there
1)Conservative
2)Non invasive
3)Invasive surgical

Initially we start with conservative management for at least 3 months-
Suggestion for conservative management are-

Start taking Syp. Lactulose 10-15ml once daily before going to bed. It is one of the most frequently used laxatives, tolerated very well by patients in long terms with minimal side effects. Using laxative would prevent straining while defecating.

-Secondly, start using Prepration H (a combination containing contains Calcium Dobesilate, Hydrocortisone, Lignocaine, and Zinc.) locally over the prolapsed hemorrhoids.

Thirdly, request your gastroenterologist to prescribe you with oral Calcium Dobesilate-Doxium therapy for 3 months. Initially twice daily for 21 days followed by once daily for 10 weeks. Trials have shown that 3-month therapy can cause shrinkage of Hemorrhoids in almost 60% cases.It was demonstrated that calcium dobesilate decreased capillary permeability, inhibited platelet aggregation and improved blood viscosity; thus resulting in reduction of tissue edema.

Get yourself examined by a MD.

Thanks.

---