I am Dr. Shamoon. From what you describe - severe constipation that worsens in the days before your periods, and a bump you can now see and feel at the anal opening - this is most likely a sentinel skin tag or an external pile (sometimes a small clotted pile) formed by repeated straining against hard stool. Progesterone in the premenstrual phase slows the gut, so stool hardens for about a week each cycle and the anal canal takes the brunt of it. If passing stool gives you a sharp cutting or burning pain that lingers for several minutes afterwards, with bright red streaks on the paper, there is very likely a small anal fissure under that tag - the tag is the body's scar response to a chronic fissure, not a tumour. The right specialist for you is a General Surgeon or Proctologist; you do not need a gynaecologist for this even though the timing follows your cycle. At 42, with the picture you have given, this is not a severe or dangerous problem and it usually settles with stool softening and local care rather than surgery - but it will keep returning every cycle until the constipation itself is corrected. What would change my advice is a hard fixed lump that keeps growing, bleeding that is dark or mixed into the stool, unexplained weight loss, or a lasting change in your bowel habit - those need examination and possibly a scope, not reassurance.
Next Steps
1) See a General Surgeon or Proctologist in person for a simple local examination - that single look settles whether this is a sentinel tag, a pile or a fissure. 2) Start warm sitz baths: sit in a tub of plain warm water for 10-15 minutes, twice a day and after every stool - this relaxes the anal spasm that keeps the pain going. 3) Fix the stool consistency before your period, not after: 25-30 g fibre daily (soaked figs, papaya, oats, whole dals), 2.5-3 litres of water, and a bulk laxative such as isabgol husk 1-2 teaspoons in a glass of water at bedtime, started 5-6 days before your expected date. 4) Never strain or sit on the toilet for more than 3-4 minutes; go as soon as you feel the urge rather than postponing it. 5) A short course of a local anaesthetic-plus-healing ointment applied gently at the anal opening after each sitz bath usually helps a lot - please take that on prescription after examination rather than picking a steroid-containing cream off the shelf. 6) Ask the surgeon to also check your haemoglobin if you have been bleeding with stool along with heavy periods. 7) If you would like me to review your photograph and periods pattern together and plan the medicines before you go for the examination, you can book a consult with me here on Practo, or meet me at Synergy Multispeciality Hospital, Miraj.
Health Tips
See a surgeon the same day if the lump becomes acutely painful, hard and bluish (a clotted pile is best treated within 48-72 hours), or if you develop fever, swelling with pus discharge, or heavy bleeding with giddiness. Avoid over-the-counter steroid creams and repeated stimulant laxatives - both worsen the anal skin and the constipation in the long run.